I think the show is poking fun at all sorts of stereotypes, by
   accentuating them, and laughing at them! I think most people
   understand that it is funny *not* because of Tim making fun of
   Jill, but of the absurdity of him saying these things. But
   perhaps, that's just me :-) *I try to never underestimate other
   people's intelligences - one might be surprised to see people
   smarter than one thinks - they just didn't want to show it off
   :-) [construction workers and others thought to be "duuh" class
   included]