I'm ROFL about the "dump him" posts. But really, if this is a huge issue for you, I'd consider moving on. Common interests can be important but not necessary HOWEVER, respect is key. Always.
My husband is a total dork lately for steampunk. Do I wanna do anything steampunky? HECK NO! However, I totally love seeing the weird stuff he creates for it. I'm proud of all of the things he makes/comes up with because he is SO PROUD (and really, they are fantastic.)
I would never tell him he's silly for liking something that is so important to him. I have told him that I totally understand WHY he likes it (he's creative) and I'm glad he found a cool/weird hobby.
I've met people who don't 'get' our love for Disneyland. We don't love characters..we don't love characters outside the parks, we don't love the merchandise (with a few exceptions) but we love Disneyland. Those people's opinions don't matter to me. . . but my husband's opinion would hurt my feelings if he said that stuff to me, ya know?
I realize that this isn't what you're asking..so I apologize for joining in the 're-evaluate' camp LOL.
You can't change someone. You can show them what you see and if they still don't see it, they probably won't. You either will need to be ok with that (and so will HE) or it might be time to explore other options. In ANY CASE, he needs some respect, yo
