Bubble screens are horizontal throws, I think you mean.
I don't recall many bubble screens being thrown in this offense, and they aren't a good response to a blitz unless the DB is laying off 10 yards.
A lot of offenses have them as a set read between the QB and the receiver: if the DB tries to hang back, the QB and wide-out both know the QB is taking a one step drop and firing the ball. At the least, you should get four or five yards out of it if the defense was in man coverage.
We don't see enough DB's lining up that deep to make it work. Even though Smith and Jones are very fast, we don't have enough branches on the route tree to make them fear having to run with them. DB's tend to be pretty fast themselves, and if they aren't afraid you'll cut off the route if they turn their hips, they don't need to line up deep.