Tesla went from "a cool tech company, and also the ceo does rocket stuff, which is kinda nice" to "what is wrong with that f*cking nazi jerk" in the last 10 years in my circles, and it is very much deserved.
Btw, note that it was not actually a Roman salute (though it may have been adopted by Italian fascists because they incorrectly believed it had been used by the Romans; they were keen on Roman iconography).