It's a matter of philosophy & situation & tendencies imo. a d-coordinator might choose to blitz if he's trying to force the qb to throw it quickly allowing the db's to sit & drive on those short routes that they know the WR's are going to be running b/c the fear of getting beat deep is pretty much non-existent.
Teams don't blitz a lot in the RZ because you are almost giving up the quick pass.
When you are in the middle of the field and you blitz, guys will play off the recievers a little bit and drive on the short routes because they figure with the blitz they don't have much time to do a double move. if the guy catches the ball, ok...Just make the tackle...
In the redzone you generally don't want to concede any yardage...and then if the WR catches the ball and the guy in coverage on them misses that's almost a guaranteed TD because now you are so thin back in coverage.
& ok, maybe zero percent was a bit of an exageration...maybe it has about 10% to do with it simply b/c even at the egde of the redzone a 20 yd. throw is nothing for any NFL qb to make & put on a rope...even for guys like schaub....As long as he can step into his throw. His arm strength issues really only rears it's head when he's throwing deep.
When throwing deep you can actually hide your arm more, by making faster reads and throwing the ball early. I think Schaub's deep ball passes have some to do with his arm strength, but where it shows up more than any other place is when he has to throw into really tight spaces i.e. the RZ.
But we can agree to disagree on this. No biggie.