I think any web forum that grows significantly (not just tech) will tend toward politics, because to talk politics, all you need is an opinion, and everyone's got one of those.

To talk about technical topics, you need some experience and expertise, and those are a lot harder to come by. So the percentage of those folks declines as the overall audience grows.

I wish it were possible to have a <s>tech</s> community that politics didn't eventually dominate.