A few years ago penalties were being handed out for that and we were up in arms because it meant drivers would be afraid to make a move if there was going to be contact, whether intended or not.
This is the situation that I don't want us to get back in to. Not every contact is a penalty, but with that then comes the problem of stewarding and being able to constitantly apply the same punishment for infringements. It's a bit like reffing football where officials may see incidents differently.
As for the Rosberg/Max incident, surely the best way to handle situations like that would be to order Roberg to give the position back rather than the time penalty. Much better than having a penalty that spoils the fight.