I think it's this.... if you walk into a board room and are tall (and well built helps I guess) you make a better impression. In business and such things, your appearance can demand attention and exude authority... you know it's all about POWER.
On film, you can create your image.... none of these actor really appear short in their films, y'know? They shoot at angles and stand on boxes and crap.... so lack of height isn't really too bad...
But that doesn't explain why there are sooo many short actors(/actresses?).... maybe they use outgoing personality or humor in school to make up for what they feel is a "problem" of being short.... I dunno.... maybe they just don't do well at sports so they find other things to do...
hmm... no sports = getting into art, music, etc.... anyone notice average height in other "artsy"/creative fields?
just a thought...
-Hex..