It's not so much that the costume looks stupid, it just becomes rather silly when presented in Nolan's "realistic" Batman universe.
I'm sure they could've come up with a more realistic catburglar/thief outfit, but I guess they wanted to do a call back to the old Adam West show.
I'm sure they could've come up with a more realistic catburglar/thief outfit, but I guess they wanted to do a call back to the old Adam West show.