I think a great part of the hating on Bendtner is due to the fact he's an arrogant cock sucker. I mean, the guys is just idiotic. Sunderland was thinking about keeping him, based on his performances (he didn't totally convince them, but had a string of good games late in the season). Then he simply loses the team bus to the match. LOL. Grabs a taxi, arrives 20min late in the pitch and the manager of course make him watch from stands. It's when they decided to offload him back to Arsenal.
In 2009 he was actually having a good season, scoring a hat trick in a CL game. But an injury fucked the rest of his season. In 2010 he had some chances to play, but after the car accident and the goal he lost against Barcelona in the last minute they decided to ship him off.