God bless Canon, who only makes good things now when forced to by a competitor.
First, the previous 35mm f/1.4L was an excellent lens. Claiming it wasn't good at all is completely laughable! The 35/1.4 L was one of Canon's best-regarded lenses for, what...at least a decade??
Second, Canon is not necessarily updating this lens
solely because of competition. It is probably a factor, for sure (third party lens makers have never been as aggressive as they have been the last five years, and they are starting to produce some great stuff.) I believe Canon has been updating their entire lineup of L-series lenses in order to prepare for a future world where the EF mount is matched with
very high density sensors that will be demanding much more from lenses than DSLRs have to date (keep in mind, it was only about four years ago that CMOS pixel density reached levels where it started producing images that surpassed the resolution of a drum-scanned 135 slide.)
Third, even IF Canon only made this lens in response to competition....well, that is the very nature of a
COMPETITIVE MARKETPLACE! One shouldn't be surprised by any
competitor in a
competitive marketplace holding out as long as they can so long as they continue to have a superior product, or a product that their customers are not regularly complaining about (and, in my experience, most people seem to love their 35/1.4 Ls...I'm surprised by the comments in this thread so far. My personal experience with several rented copies has been nothing but excellent...does no one use AFMA?) The best time to one-up the competition is when the competition is trying to one-up you. No point in spending hundreds of millions of dollars designing new lenses when neither the competition, nor marketplace, nor sensor technology are demanding them.
Those factors have only RECENTLY changed...so, Canon is updating and competing...wow, shocker.