Might want to be careful about your last statement, WH. While I understand your frustration, and agree to some point, taken to the extreme would signal a return to pre-Lombardi dictatorships where the RB was FORCED to hit the assigned hole regardless whether or not it was open or stuffed.
We should probably coach the RBs to take a middle approach, including the old DBs adage of keeping one's head on a swivel. If the hole is blocked and the outside either way is open, then take it. If not, then cut the losses by taking the assigned hole. If we held every RB to the hole, then that incredible Marcus Allen run vs. the Redskins (I think) would never have happened.
Of course, this occurs strictly on plays where zone blocking is called. Unless the defense has a huge brain fart, one is not going to see many successful cutbacks behind drive blocking.
I guess what I'm trying to say is that there's some merit to what you're saying, WH, but it can't be taken to the extreme. Like with many things, moderation is the key.