"Cos Play" (costume play) the kids call it. Adopting an alter ego or characterization of your personality, hopes, dreams, wishes and not least of all your fantasies! The only difference between
having a fantasy and
living it is having the guts to go for it. Over the top musical groups have been doing this since before KISS, but just cos you can't rock doesn't mean you can't slip into a costume and enjoy yourself once in a while. We don't laugh at country music fans dressed up as cowboys (well I do...) but very few of those drunken line dancers would survive 2 minutes in an actual rodeo roundup. You can be a superstar in your own neighborhood. If certain people can't take it, they're the ones who need to see someone in a costume (or put one on) most of all!
The police, firefighters, doctors, the army and the clergy all wear costumes if you think about it. We generally say "uniform", but what is a "uniform" if not a "costume"? It is only semantics (perception changing verbiage) that makes the difference.
I think costumes are hilarious and great. I think we need to see more people running around dressed as superheros, fantasy / historical characters or cowboys.
My first job was as a barker at the Renaissance Festival for 5 years, so I guess my opinion on this is a bit swayed!