In my opinion, this is incumbent on the crews themselves. There is always a chance of commuting in early, seeing your friend in the crashpad (or a company provided hotel, etc) and staying up too late talking to him and not getting enough rest. It is impossible to enforce enough rest without having a chapperone stand outside your door all night (even then he doesn't know how well you are sleeping).
Had the pilots in question commuted responsibly, I believe the accident may still have happened, because their training/reaction/procedures/prior failures/whatever would still have guided their decision making.
They will never regulate commuting, it would be too expensive. Just look at the carveout for cargo ops. The FAA caved on that saying it would be too expensive for the industry. They wouldn't even come close to regulating commuting for the same reasons.
We all know people who get up at midnight and drive 4 hours to show at 6am, and we all know people who commute in early to be rested.
Bottom line is we need to all be the proffesionals that we are, and part of that means commuting responsibly. We all complain that the airlines do a horribe job of self policing on many things, let's be an example of how to do it right.