I don't understand what you mean. People in your province voted against their own interests because they believed (incorrectly?) that it would benefit them? How do you know what their interests were or whether it did benefit them in ways that were important to them or not?

Do you believe people have perfect knowledge of the consequences of their vote, and of the plans of the people they vote for? If no, then it's not hard to fathom that people can get manipulated into voting against their own interests.

Sure they can but you're not exempt from that manipulation so your own evaluation of their interests and what they're voting for is just as subject to manipulation and thus you can't tell if it's in their interests or not any better than they can. The difference is they're responsible for their vote, not you.

atoav called the government a "a neo-nazi connected right wing party". It won't actually be neo-Nazi because that's surely illegal in Austria. So it's probably some kind of propaganda that led him to believe that or exaggerate its significance as being against the interests of non-Nazis. Maybe they offer something their voters want and their voters don't care about whatever media-hype-hate-frenzy label they're given.