I don't think the goal is to discourage it. I'm pretty confident in assuming this goes on all over the league, and I think if you got the commish to be honest, he'd tell you he's pretty sure of the same. Where the problem was is in the fact that they got caught last year, were warned not to do it again, the rule was put in place over the offseason, and then they blatantly did it again on Week 1, using the same guy and all. Belichick basically told the commish to go screw by doing that. Hence the punishment, which was fair if you ask me.