I'm sure you're right, which is why I'm moving away from ads. The examples that give me some sliver of hope are reddit and tumblr, both of which have some form of ads.
Well, you'd think that Google could pro-actively not show ads on occasional 'bad' content rather than putting it on each individual website operator to avoid displaying the adsense iframe (or whatever it is) on content that might bother Google. They're already identifying it.. why not just not show the ad? And then only penalize accounts that have a really big % of unadvertisable content.