But they've already got the 14mm f/2.8 and 16-35mm f/2.8. If they make a 14-24mm f/2.8 then that's one lens that you'd have to buy instead of two, why would they do that and drop sales of their €2050 prime? [/sarcasm]+1
If they make a 14-24 f/4 then they can keep all 3 models, 14mm f/2.8 prime (€2050), 16-35mm f/2.8 fast zoom (€1270), 14-24 f/4 slower but wider zoom (would slot nicely in at €1800?). Then the 17-40 f/4 becomes more of a "My First Wideangle L Zoom" lens on the cheaper end (currently €690). I'm not expecting a 14-24 f/4 zoom to be much cheaper than the 16-35, although it could go up a bit higher than the 14mm prime depending on IQ.
A 14-24 f/4 would blend in perfectly. If it would be razor sharp.
I like that idea, because the landscape & architecture fotos I make are usually in acceptable or better light conditions. So such a lens would be well suited for travelling...
For poor light, I would prefer a good wideangle prime.
My 2 cents