You can't really blame the beta because beta tests tend to only hurt games which are (particularly) bad ... many of the biggest and most popular games have very large beta tests. What it comes down to is that Little Big Planet is the round-peg to the PS3's userbase's square hole.
When you have the PS2's 100+ Million userbase you have a wide variety of users who are looking for a lot of different kinds of games and (most) good games can find the audience that they have earned; in contrast, systems that have yet to achieve particularly large userbases tend to be fairly focused on a couple of genres that do well and outside of these genres games struggle.
Now the sales of this game certainly justifed the development of the game, and possibly have covered all costs (including marketing), but didn't live up to the expectations of some members of this forum who were hyping the game endlessly.
