All cognition has an emotional component, so you have to be more specific. Once you get more specific, then you'll see that music and art communities are different.
This is true on algorithmic platforms that reward "engagement" of any kind. I didn't get that sense from pre 2010 Facebook or Twitter and I don't get that sense on fediverse platforms.
What makes you think a post has only one point? It's a curious notion, but I would imagine the vast majority of posters have multiple reasons for sharing what they share.
Obviously people are often posting things they think others might care about, but that doesn't tell us anything about anything at all.