That's exactly my point. No mainstream (even partisan) view is supporting monopoly. Such views are normally expressed by corrupted politicians and paid shills. Or you are suggesting that supporting corruption is now mainstream or that some party now is officially against free market even without being corrupted?
Supporting companies against excessive regulations in general and supporting monopolies (i.e. preventing antitrust restrictions and supporting aticompetitive market capture) is not the same thing. The first should serve freeing the market. The second serves only reducing its freedom, nothing else.
Also, consider that exactly the same companies who are against enforcing Net neutrality are perfectly fine with the politicians which write for them state laws which ban competition. I.e. blatant excessive regulation, and very unhealthy one with that. Those are the same companies and politicians which at the same time scream about how bad regulation will be if Net neutrality will be enforced. Hypocrisy much? Or may be they simply are against regulation which weakens their monopoly and pro regulation which strengthens it?
As you can see it has nothing to do with partisan or "mainstream" views on regulation in general. It's about greedy monopolists and their bought corrupted bureaucrats. Who in their normal mind would voluntarily support such a thing?