I've only seen a couple of MCU movies and a few (mainly Batman) DC ones, never much cared for the comic book medium but for a few exceptions; however, I don't really see what you're describing as a problem among my friends who do really get into that stuff. You can find obsessive fans for anything, I don't think most people who get into the MCU are particularly obsessive though.

Also, while the franchises have moved away from being for young kids anymore I can tell you that my friends who have kids in the teenage bracket certainly bond with them over their shared interest in such movies.

Disclaimer, I don't really sort humor into high brow and low brow per se, and probably listen to a whole lot more than 20 bawdy or indecent jokes in a single day. There are plenty of comedians who are too mean-spirited for my taste though.