Meanderings of a Film Lover

I find it baffling that the powers that be in the movie and televsion biz don't understand the concept "too much of a good thing". We all know that the best characters in a movie is usually the zany wacky off the wall character.  That doesn't mean we want to see more of them though, the reason that they are so good is that they don't over stay their welcome.  With "Get Him to the Greek" recent release based off of the Aldous Snow character from "Forgetting Sarah Marshall" to the newly announced plans for a Less Grossman movie based on the character from "Tropic Thunder".  While both of the original films were very funny and the characters are funny in their own right.  Neither of them has the depth to carry a movie in my opinion.  Trust me, I saw "Get Him to the Greek"  and between the occasional laugh, was mostly boredom.  TV is no exception.  I love Sue Sylvester on "Glee", really the only thing I like about the show, but put her in more than 25% of the episode and it has gone into overkill mode with her. Kenneth on 30 Rock, also has gone into too much of a good thing category. Can I be the only one who doesn't need a character shoved down my throat in order to enjoy them?  Why can't the entertainment industry grasp the "Leave them wanting more" concept?