it's not, but that doesn't mean it is a good idea to just refuse them. unless the relationship is seriously broken, it is always a good idea to to try to work on the relationship with your parents and avoid making it worse. if this is the only issue i'd have with my parents, it would be better to try to resolve the issue instead of rejecting them.

I think people may be projecting some very strange personal feelings about their parents on people they don't know.

possibly, but i get the same impression from your message too. you may have reasons for your choice that are not visible from your post, which is fine for your choice. but because i can't see those reasons (and it would be out of place to share them here) i have to interpret your message based on the context available.