Well, like an earlier poster said...todays Digital Camera really isn't so much a stills camera at heart..it IS a video camera at heart, that is specialized to take good stills.
This may apply to MIRRORLESS digital cameras, but like all SLRS, DSLRs are dedicated stills image cameras, which have been "tricked" into also being able to capture moving images (video) by bypassing the defining elements of any SLR: mirror and optical viewfinder. To get there has caused massive R&D cost. I would prefer if this additional, video-related cost [sensors + electronics to handle video in addition to stills capture] would be unloaded on those people who absolutely want cameras that can capture both video and stills rather than making people pay for it who only want one functionality from their camera. Capturing excellent stills images and having an ergonomical interface that is 100% dedicated to getting those images.
This is why it would be fully justified and perfectly fair, if "dual use, video-enabled" versions of a DSLR were sold 10-20% more expensive than single-use stills-only versions of teh same DSLRs.
And once the clients would be given this choice, it would become very clear that only a very small minority of customers really need the dual functionality and are willing to pay for it (since it is still a lot cheaper than purchasing a dedicated stills and a dedicated video camera) but many more are just clamoring for video in stills cameras, because right now they are getting it "free of charge" [as stills photographers pay for it] and "might need it once in a blue moon".
Hmm...now, another way to read what you said was...that DSLR's are basically video cameras, that had a lot of R&D money put into them, to figure how to put in the mirror and other mechanisms to enable stills pics in the same way that older SLR film cameras operated...that the R&D money went into basically taking a digital video recording sensor paradigm, and adapting it to emulate old SLR functionality film cameras had?
Seriously, depending on where you stand...it could be read that way.
Still, I stick by my thoughts that today's DSLR...if you "took the video out of it"...at the manufacturers side, they'd save maybe $1 per unit not putting on a couple of jacks, and they might cut the cost to the consumers by maybe $100-$200, and basically it would be the exact same camera, sans jacks and having some of the software there disabled (not gone mind you, just disabled).
It would be similar to things like video cards or even versions of MS Windows...where they sell different versions of the things and different prices.
The thing they're selling often is the exact same product, but artificially making some versions inferior by disabling features that are there, but disabled and sold at a lower price.
People get pissy about it when that happens....so, I guess that means you can please everyone.
Heck...if you wanted to look at say the 5D3....it actually is somewhat disabled. Look how Magic Lantern is in some respects "unlocking" functionality in the camera and system to get things like RAW video out of it...that Canon didn't fully use or purposely disabled.
One could complain that Canon isn't fully utilizing or allowing utilization of the hardware we have already bought.