They certainly could have limited it to the the reduced frame cameras they already had, the D30, D60 and 10D; they could have done something like what Nikon, Pentax, Konica-Minolta, Sigma, Tamron and Tokina are all doing: design a 17-something lens for the "APS-C" image circle, compatable with their existing EF mount.
Well, judging from what I've read of the 17-40L, it seems that it's a lens doing exactly this; it's optimized for a reduced image circle (up to the APS-H -- 1.3x -- models), yet utilizes the same mount.
Someone please correct me if this impression is wrong.
That less extrem wide angle design would have allowed some combination of lower cost, lower weight, and less restricted zoom range, and would have been of great benefit to owners of their early 1.6x DSLR models.
Compared to the 16-35L (and formerly, the 17-35L), the 17-40L certainly has a greater zoom range (a minute difference, I agree), lower cost (this difference is significant) and lower weight (475g vs 600g for the 16-35L).
In fact I have still seen no good explanation of why the shorter back focus of EF-S designs is useful, apart from some mild cost savings mostly relevant to lower level lenses
I thought the shorter back focus also made it easier to cut down on weight and made optics a bit easier to handle.
The EF-S 10-22 weighs only 385g, and is insanely
wide for a zoom. But no more so than the 16-35mm is for a FF 35mm sensor.
Another intermediate option might have been making it cover up to 1.3x, with a bit more zoom range like 17-50 possible due to the less extreme wide angle design, to give 1D owners a more useful wide angle option.
That's what's sad about using a 1D (MkI or MkII), you just won't get a really wide angle zoom from Canon. But could they even have made something similar to the 10-22 viable for the APS-H format? From what I see in my own pictures, the vignetting is already significant with a 20D, a 1D would make it awful.
I guess the complaints about the qualities of the 10-22 on a 1D MkII would be similar to the ones seen on naturfotograf.no about the 17-40L used on a 1Ds MkII.
It's a good thing we can turn to Sigma and Tamron, no?