This incisive critic appears to have hit on an important truth regarding the appeal, or otherwise, of stand-up comedians:
5 months ago 4 
Has anyone else noticed that the only good female comedians are the ugly ones? Jo Brand, Joan Rivers, Jenny Eclair. It's the same with men. If you're too attractive then the audience can't identify with you, and if they can't identify with you then they won't laugh.
