Monroe is a center who is not very good defensively.
I don't get the hate on Monroe. He just turned 24. To say he's not very good at something is a little overblown. Does he not block shots ? Not really. Blocking shots doesn't mean you're not very good defensively. The game is far more than blocking shots at the Center position. Sure, having an intimidator in there would be nice, but again, doesn't mean he's weak defensively.
For me, he's a rising star and still developing his game. He thrives around the rim and provides solid rebounding from the Center position.