It's pretty funny to say that Rossi did the right thing, or he didn't hurt himself, because he was too slow to beat Lorenzo the last race, anyway. What you are saying is that you and Rossi knew what was going to happen in the future. Thus, him starting from last was okay. rofl.
He lost three points for Malaysia, which gave him four penalty points for the season and mandated that he start from last the next race. Repeat: He had the same points as if he finished fourth. He gained nothing by pushing MM wide, except 20+ grid positions.
No one predicted the future. And no one knew where he would qualify or finish the last race. If he hadn't been penalized, he could have killed Lorenzo the last race and would have been bequeathed the championship. Something that I am sure also-ran Edwards would do for him. To state that Rossi didn't really hurt his chances in Malaysia is either disingenuous or delusional, just like Rossi has been about the whole damn thing. ;-P