it is a way of showing the repression and, perhaps, DEpression that almost everybody in hometown feels. Mettaton gave up on their/his dreams, asgore's divorced as hell, that one rabbit can't walk her brother
etc, etc
and you can't argue that the people of hometown aren't repressed, because that's where dark worlds and their escapism factors tie in.
They're an escape from the dreary hometown, where sure, everything's fine, but everybody's got problems, nobody's fully open.