My annoyance with him is hardly without merit. I admit I'm not in his demographic, but still feel he's nothing but a teenage cash cow.
I just find it strange that people hate someone because of their music. Your reason for not liking him is honestly the first logical reason I've heard. The other reasons people will have for not liking him are "HEZ GAAAAAY", "HIZ VOICE IZ HIGHER TAN MAH LITTUL SISTAS", and "POP SUCKZ BAWLZ, METUL F4EVUR!!!!"
I don't like his music, so I try my best to ignore him. But when people make hate threads about him or make threads about him and people come on flaming him, ignoring him can be very difficult.
I hate him because I get the feeling that he's in it for the money, endorsement deals, and the women. Not for the passion of music or the expression of emotion.