Because he didn't have to be anything else. He was hometown royalty and he was good-looking, so he was popular. Of course he was a "nice guy." He got nearly everything he really wanted, aside from that injury derailing his sports career. I thought it was interesting that he spent very little time worrying why Lisa had transferred her affections from his sister to him. It showed how self-absorbed he actually was.
He would have been an awful leader.
Innsmouth Free Press
http://www.innsmouthfreepress.com

Contrast with Tracy. He's a genuinely nice guy with good intentions and someone people want to follow, but he's not very bright or ambitious. On the other hand, Tracy's a complete and utter bitch and ruthlessly ambitious, but she is smart, she knows what she wants, and she goes for it.
Death Awaits (Horror forum)
http://w11.zetaboards.com/Death_Awaits/index/

You're making the case for how great a leader Tracy Flick actually is. He paled in comparison to her as a candidate.

My high school contained many like himathletic and attractive but thicker than glue.