just_chill

It is tricky to get someone to recognise that they aren't knowlegable enough. Even if you say it as gently as possible, some will still hear "you're dumb" and no one likes that.
Also it's a great tool to manipulate people : "I don't need a scientist trying to explain me life from the depths of their lab !! I have commonsense !!"

You need a bit of knowledge to get the most out of a complex music, which sounds intimidating.
Or you can just go to the concert blind and take in all the emotions, but people don't know that's a perfectly valid way to enjoy classical music. (It is! go to the concerts and don't be afraid to have an opinion)

The history of elitism is definetly there, and instruments are not cheap, which attracts up-their-arses kinds of people, you are absolutely correct. But also they are people who just like the historical aspect of it and want to play an accoustic instrument ! Also you don't have to dress to go to the opera or concert anymore. If someone looks at you weid, they are the weird one !
May I ask whether the ones you have been speaking to play themselves? Most musicians I've met were chill about it, maybe it's different with listeners?

playing in a symphonic orchestra. sure, it sounds cool, but most people don't know much about the topic and feel intimidated by it, so the conversation is just me attempting to convince them that it's not just for rich nerds and you can be casual about classical music.