I was thinking this and it may have some truth to it.
We all know that the "Busey class" in the Malcolm In The Middle world is for the "crazys", the "strange" etc. Well there is this actor named Gary Busey and has really been known for his insane behavior in his work and outside.
The writers. Let's see, there's Glouberman, one of the Higgins brothers, Meg someone or another--at least, it was that group. I believe they got a whole new group 7th season. At the beginning of the ep, it usually gives that credit.
Lol! I knew it was only a matter of time until Gary Busey was dragged into this! Yeah, I have kind of suspected they named the class after Gary, since he is an extremely weird comic actor(funny, but just really weird). See one of his shows and you will know what Im talkin about.