Google has to choose something to prioritize. It's good that in this case it chose the authoritative site over the conspiracy theory one. Even better if they chose it because it was more authoritative rather than because they calculated they could show you more ads that way, but I won't give them credit for that just yet.

They didn't censor the other site completely. If I search with site:dangersofvaccines.com I get results from it. I can't get results from it any other way though, including searching text that only appears on that site - they'd rather tell me there are no results - so I agree that's an unpleasant level of censorship/nannying.