Because Q was a purple-lipped lame-o. Not as annoying as Lwaxana but close.
The question should be "Why were there any Q episodes?" And I mean on DS9 -- do I? As I've said in some other thread, there was no reason to have so many Q episodes. Sure, they were entertaining. But they didn't really help us learn anything knew about anything... did they? Compared to TOS, TNG had too much recycled material. I guess they were too comfortable with the show.
Q-Less makes for an easy transition.... it makes viewers understand how this show will be unlike TNG.