The more intentionally “scary” the clown is, the less bothered I am. It’s the “totally normal” clowns that are freaky. I think it’s the makeup. Perhaps a bit of the uncanny valley at play. I also find insane over the top drag queen makeup to be creepy. (Just to be clear, I have no issues with basic drag, crossdressing, or trans people.) It’s the over the top makeup that makes them look like clowns or aliens that creeps me out.