Why not EF-s "L" lenses?

[Rocky]

It would certainly be possible for an EF-S 35mm lens to outperform an EF 35mm lens, but that would not be because designing a 35mm lens to cover an APS-C image circle is equivalent to designing a 56mm lens for FF.  Focal length is the distance from the rear nodal point to the image plane, regardless of the sensor size.  So, a 35mm lens for APS-C still must be designed with a 35mm focal length.  The mirror on an APS-C camera is only ~9mm shorter (vertical dimension) than that on a FF camera, so an EF-S 35mm lens can would still require the retrofocus design you need for wide angle lens.

The real benefit to the EF-S format is that the image circle is smaller, which means the elements of the lens can be smaller in diameter.  In the case of the inexpensive kit lenses, that usually just means less glass can be used, so the lens can be made more cheaply.  But, it also means the for the same cost and lower total weight, they can include more elements in the lens design, or better-made elements (e.g. molded glass instead of a resin replica for aspherical elements), or both, and that increases the ability of the lens to correct for aberrations - i.e. better IQ.

You are right. the reduction of 9mm between the back element of the EF-S lens and less than half of the covered area will definitely give the 35mm EF-S  an edge to giveuis a better lens. It still needs retrofocus design as you mentioned. But the design should be a lot esier. Therefore the EF-S 35mm can be made better than a 35mm EF.

[neuroanatomist]

Therefore the EF-S 35mm can be made better than a 35mm EF.

Can be.  But will it be? Canon may very likely sacrifice IQ to keep cost low (Nikon's 35mm f/1.8 DX is $200).  The current 35mm f/2 on APS-C is optically better than the 18-55mm f/3.5-5.6 IS kit lens, and actually delivers IQ similar to the excellent 85mm f/1.8.  How much optical improvement do you expect from there? 

The main complaints about the 35mm f/2 are that the build quality is poor, no USM, etc., and if they release an EF-S version of the lens, I doubt the build quality will be all that much better (assuming their target market is similar to Nikon's for that lens, they'll price it accordingly, and it will end up with build quality closer to the 18-55mm kit lens than to the 60mm macro).

[Rocky]

Therefore the EF-S 35mm can be made better than a 35mm EF.

Can be.  But will it be? Canon may very likely sacrifice IQ to keep cost low (Nikon's 35mm f/1.8 DX is $200).  The current 35mm f/2 on APS-C is optically better than the 18-55mm f/3.5-5.6 IS kit lens, and actually delivers IQ similar to the excellent 85mm f/1.8.  How much optical improvement do you expect from there? 

The main complaints about the 35mm f/2 are that the build quality is poor, no USM, etc., and if they release an EF-S version of the lens, I doubt the build quality will be all that much better (assuming their target market is similar to Nikon's for that lens, they'll price it accordingly, and it will end up with build quality closer to the 18-55mm kit lens than to the 60mm macro).

You are right again.
May be Canon marketing have an idea that people like to think " Mine is bigger than yours". So APS-C  user are  forced EF prime lenses. For the deep pockets they go for BIG prime L lenses. For none deep pocket, they use non-L prime lenses.
Unfortunately, I am from a slightly old school . I like it small and  good.  That is why I am longing for good EF-S prime. As for the pricing, If the 7D user will spend $1600 on the body only, I am sure that they would not mind to pay for a EF-S good prime (optically and true USM) with the price close to the L lenses with smaller size and weight.
I know, I am the minority.

[neuroanatomist]

That is why I am longing for good EF-S prime. As for the pricing, If the 7D user will spend $1600 on the body only, I am sure that they would not mind to pay for a EF-S good prime (optically and true USM) with the price close to the L lenses with smaller size and weight.
I know, I am the minority.

Unfortunately, you are.  As a group, 7D users are in the minority - in the APS-C segment, Canon sells a lot more Rebel/xxxD cameras than xxD or 7D, or even the latter two combined.  Canon's best selling lens is the EF 50mm f/1.8 II, which is similar in design to the 35mm f/2 (although even lower in build), and it's no coincidence that the nifty-fifty is also their cheapest lens outside of a kit purchase.  My guess is that Canon's marketing department will try to capitalize on that, and an EF-S 35mm f/1.8 in the sub-$200 range would garner more profits from that segment.

You have a 7D...for better or worse (and it's definitely worse from the standpoint of a prosumer's wallet!), Canon wants you to buy the EF 35mm f/1.4L.  Then they want you to buy a 5DII to use the full image circle of that fancy L lens.  Then they want you to buy the 50mm f/1.2L so you can get the same framing you liked with the 35L on APS-C.  Etc.   

[Freshprince08]

That is why I am longing for good EF-S prime. As for the pricing, If the 7D user will spend $1600 on the body only, I am sure that they would not mind to pay for a EF-S good prime (optically and true USM) with the price close to the L lenses with smaller size and weight.
I know, I am the minority.

Unfortunately, you are.  As a group, 7D users are in the minority - in the APS-C segment, Canon sells a lot more Rebel/xxxD cameras than xxD or 7D, or even the latter two combined.  Canon's best selling lens is the EF 50mm f/1.8 II, which is similar in design to the 35mm f/2 (although even lower in build), and it's no coincidence that the nifty-fifty is also their cheapest lens outside of a kit purchase.  My guess is that Canon's marketing department will try to capitalize on that, and an EF-S 35mm f/1.8 in the sub-$200 range would garner more profits from that segment.

You have a 7D...for better or worse (and it's definitely worse from the standpoint of a prosumer's wallet!), Canon wants you to buy the EF 35mm f/1.4L.  Then they want you to buy a 5DII to use the full image circle of that fancy L lens.  Then they want you to buy the 50mm f/1.2L so you can get the same framing you liked with the 35L on APS-C.  Etc.   

+1 on this.... I'm making this exact journey - my 35mm f1.4L is arriving this week. Goddamn those cunning Canon strategists....

[Edwin Herdman]

What is most immediately evident (even in the store) when you compare EF and EF-S is not that designation, or a reduced image circle, but all the small psychological boosts of the newer lens over the older.  Again for the Nikkor 35mm lenses, over the f/2 version the newer DX version boasts stuff you might notice in a shop:  Slightly wider aperture, newer (and better) focusing system, price.  There are a handful of losses compared to the f/2 but most only become apparent on testing (DPR found a high degree of vignetting on the DX which makes perfect sense when you try to widen the aperture whilst keeping the front element about the same size).

[WarStreet]

You have a 7D...for better or worse (and it's definitely worse from the standpoint of a prosumer's wallet!), Canon wants you to buy the EF 35mm f/1.4L.  Then they want you to buy a 5DII to use the full image circle of that fancy L lens.  Then they want you to buy the 50mm f/1.2L so you can get the same framing you liked with the 35L on APS-C.  Etc.   

Funny. One of the reasons for me to go FF, is to use the full image circle, then I will need to get a standard zoom, and also a 135 to get the same framing of the 85. Seems Canon will achieve their aim !

[neuroanatomist]

You have a 7D...for better or worse (and it's definitely worse from the standpoint of a prosumer's wallet!), Canon wants you to buy the EF 35mm f/1.4L.  Then they want you to buy a 5DII to use the full image circle of that fancy L lens.  Then they want you to buy the 50mm f/1.2L so you can get the same framing you liked with the 35L on APS-C.  Etc.   

+1 on this.... I'm making this exact journey - my 35mm f1.4L is arriving this week. Goddamn those cunning Canon strategists....

LOL.  Been there, done that.  7D + 85mm f/1.8.  Wanted more OOF blur, so got the 85mm f/1.2L II.  Got 5DII.  Then got 135mm f/2L. 

That first lens with a red ring is called a 'gateway lens' for a reason.....