"I have never encountered an individual who claims to hate the 'elite'"
I don't know what to tell you there. Go talk to more individuals? Go read some right-wing propaganda (e.g. almost anything that comes out Josh Hawley's mouth, or certain off-bench remarks from Justices Alito and Thomas--and yes, all of these individuals are also "elite", but because their views are in the minority among elites, they can't like they aren't "elite" and rail against the other elites).
Go see who likes them, how it plays with that base, and see also how it plays with the far-left camp (e.g. Bernie, who I generally like but who has a lot wrong, and AOC) too, though they may use different language. It's a pretty popular meme (I wouldn't call it worthy of being labeled an "idea") among certain segments of the population, sometimes for different reasons.
"And what do you mean by 'elite' anyways? If people dislike those in the position of authority, especially politicians, they generally have very good reasons for that."
I was not thinking of politicians, but, fwiw, I would say blind/reflexive hatred of politicians is a prime example of a kind of idiotic and adolescent trend in American culture to just hate traditional authority figures.
There are probably plenty of good reasons to hate them, sure, but ask people who say things like "oh yeah they're all corrupt" how they know that, what evidence they have, whether they can list the past several major corruption scandals, how corruption here compares to other countries, etc, and they can't do it at all.