The cars are much better than the competition at the price point, the software and updates are far ahead of the slow clunky interfaces that are never updated. Dealers charging $400 to update maps is BS. People gush over them and it spreads word of mouth.
The green aspect makes it popular among moderate liberals, only the immoderate folks stop buying Tesla because of politics. And they're not as numerous as they think they are, because they drown out positive news and opposing opinions in their online circles like on HN.