Lots of reasons. In a nutshell, I honestly think it's extremely likely that this is one easy way to make the market work against the industry.
Think of it, if I can get industry players to pay me, say, $20/mo for advertising that either doesn't help them or even works against them, that's small potatos. But if it works out that way (and I'm not there yet, still watching) then what if all 300+ of those kids w/ MySpace pages did the same? Then all of the other sites that present a critical view of the industry did the same? It would be a burdon on the industry AND a subsidy to the opposition.
Now, theoretically, they can all block their ads showing up in whatever site they want. However, they've been wreckless and sloppy about encouraging any old huck who fell for their scam to go ahead and put up a page somewhere and buy some advertising for it. Websites are like children in a couple of ways. Very often, the entheusiasm of creation doesn't carry over into maintainance and they don't always perform as you might have wanted or expected going in.
Besides that I simply resent the worst players, the most scurrilous and sadistic assholes in our society having so much control over our economy. It
IS our economy, ya know! They're making us look bad. Hell, even some of the best among us often state their belief that all of Western society is corrupt and cruel and evil. Bullshit! We're not. We're just wimps, that's all. That's easy to fix if ppl just come to understand that it needs fixin'.
I could go on. The only reason why I didn't do this 2 years ago is that I knew it would take a lot of time and attention--both on the practical end of seeing the experiment through and on the social end of duking out the ethical issues as we're doing now. So I put it off. But I have given it a lot of thought.
All national institutions of churches, whether Jewish, Christian or Turkish, appear to me no other than human inventions, set up to terrify and enslave mankind, and monopolize power and profit.
--Thomas Paine, American revolutionary