A lot of people present initially as quite boring, or at least with narrow interests and wholly conventional manners. Personally, I absolutely love a little flicker of acknowledgement from someone at the school gate that, say, living in late capitalism is not the best thing for our wellbeing, or maybe a small bit of evidence of an artistic perception, or spiritual sense, or irreverent humour...or something, something that elevates two people talking, to a teeny hint of a discussion of the human condition, the arc of history, the discovery of science, or what have you. That isn't the same as people being swanky or show off or unkind and I don't mean a world where we are all.deliberately intellectually snobbish. It doesn't mean everyone has to wade in with a philosophical treatise in the Co-op.
It's just, in conversation, revealing a bit of humanity and a bit of perceptiveness about society, a bit of general insight, rather than staying hidden behind the neat veil of social mores and conventional tastes. I like people who stick their necks out to do this, in tiny ways.
I know why people don't reveal these things though. They are either playing it safe, or waiting politely to take the lead from others, or they don't want to foist other concepts into the everyday (Funny thing about sex parties, right, is...).
Or, these vistas haven't occurred to them, and they think only on a purely surface level.
The last one of those is the least likely, so I think OP is just not finding the right way in with people. But it can be the case that some people don't value this meeting of minds, this small mental double take, and don't like shifting a concrete idea to an abstract one, so they don't do it as a matter of course. It's important to me and I like people who do it.