If by corner route you mean redzone fade, then it's simple why we run it so often: it's the best route in the redzone. You can only commit one player to the receiver, therein making it the safest throw. Add on top of that Eli's accuracy, and Nicks' ability -- when healthy -- to outman a corner, and it's a slam dunk play.
My guess is everyone would prefer throwing TE seams in congested zones, seven yards before the goal line.
Take into consideration what kind of options open up when this play can be successfully ran. If a receiver has the option, and a corner cheats, he can just run the slant. If the fade is designed to the Z receiver, and the defense commits a safety to him, the Y runs a seam and is likely to score.
Very important route to establish. This thread blows.
it is very important I was just saying we went to it a lot with very few positive outcomes that's all...so EAD