I guess my milage varies. I've been in the "ivory tower" in various capacities and haven't seen much of a disdain for "normal" people. When you go out with profs and grad students drinking at the pub, nobody is talking very high-minded. :)

Not to say there aren't some that show such a disdain. Still, in partial defense, if something falls into the particular area of expertise of someone, its hard to listen to someone with a slight interest in the area as being equal, especially if they have some problems with the basics.