I'm definitely uncertain about what bad politicians would do with control over the net's structure. I do know exactly what the CEOs of major ISPs will do though: they will maximize short-term profit. I've seen a lot of short-term profit maximization in my (rather short) life, and I haven't seen any of it turn out well. We used to have companies that had long-term goals, fundamental research divisions, the ability to see past next quarter's profits. I'm not sure where those companies are now, but if they're gone, it seems that the government is the only entity left that can have a long-term goal. Of course, long-term for our (US) government tends to be the election cycle, which is 2, 4, or 6 years. Not good, but perhaps not as bad as it could be. It's also easier to change the government than it is to change a huge company, although neither of those things is an easy thing to do.
I'm not sure that net neutrality is quite as sweeping as you see it either. If congress is getting into peering agreements, protocol design, things like that, then we're definitely all doomed. If they're just slapping down anti-competitive measures like charging companies for access to ISP subscribers, then I can definitely get behind that. It's a matter of degrees, I guess.