[vacri]

I think it's because generally as you get older, you realise that winning office politics points doesn't really give you any reward. Any small moment of gain is fleeting, and you exchange that for destructive behaviour.

It's not to say that older people can't be petty, just that proactively engaging in politics seems to be seen as not particularly worth it. My frame of reference is that I've just turned 40 - I will probably feel differently again in 10 years :)