Why was Baby's Day Out a flop?

My mum and I were talking about this movie a few days ago and she was suprised it wasn't a success. I agreed seeing as John Hughes was tied to it. Seeing as he made so many popular movies, you'd think this would be one of them.
I just don't understand why the film bombed. It only made $30 million against a $48 million budget. Why was this movie such a box office bomb and what could have made it a success?