That's partly because the experience mostly is that they don't taste very satisfying. If I ever tasted vegetarian food that satisfied me the same way bacon or beef does, I'd happily eat more of it. Not ever gotten anywhere close, though.

So I don't think it's so much cultural beliefs as it is experience, coupled with exactly the idea that it is "fake", and coupled with a stereotype of smug vegetarian eating food that people don't expect to taste very nice for ideological reasons. It's associated with choosing away nice tasting food, basically.

Reducing the meat content and adding more of various substitutes would probably work a lot better to change habits than trying to get people to pick vegetarian food, and open the door for cutting more later.