I don't understand why people are ganging up on bananaking. The OP asked a question and bananaking gave his answer. Which is, the question doesn't make sense because Sony did make a 2D platformer with LittleBigPlanet. Sure, he thinks LittleBigPlanet is the superior game, so what? He has the right to his opinion, and if he wants to support his opinion with reviews, then he has a right to do so. If you really have a problem with people mentioning LittleBigPlanet, then you should have never entered the thread to begin with. By reading the title and getting a jist of only the premise of the thread, it's clear what the OP's purpose is, and it's even more clear what the subsequent answers will be.
Also, doesn't matter which game is better between Mario and LittleBigPlanet. The OP did not imply that Sony's outing would have to be on par with Nintendo's outing in order to be mentioned, otherwise he would be implying that PABR is on par with SSB, which I'm sure he is not. So attacking Bananaking for saying LBP is the superior game doesn't have anything to do with the thread (it seems more like people can't handle someone with a different opinion). The OP merely wanted to know why Sony didn't tackle the 2D platforming genre, and he responded that his question was flawed, because Sony did make a 2D platformer with LittleBigPlanet.
Quality is subjective and these games are different enough for there to be different valid opinions. On one hand, LBP scores higher, one the other hand, Mario sales more. Niether of which is an absolute indicater of quality. And niether of which are relevant at all; the OP never asked for a higher quality game. So not only has this argument been childish from the beginning; it's also both flawed and irrelevant.