Wouldn't it be better if instead of a longer range, we got a shorter but higher quality luminous zoom?
Say... 15-45 F2.8?
Then the 15-85 could be improved to continuous F4... giving us two choices: zoom range vs speed.
I don't know what a luminous zoom is, nothing on Google either.
All Zoom lenses are a compromise, shorter ones compromise less, but if you get too short a zoom, then you can just use a prime. The biggest market for low cost EF-s zooms is from the Rebel users, who are not camera enthusiasts, they had a long zoom on their P&S, and want one on their DSLR. Even a long Zoom can be a big improvement over a P&S with a superzoom, so the buyer is very happy.