Every episode was innovative and different, it introduced new characters in almost every episode, had funny recurring characters and had some great acting.

So why did this show get cancelled?

i don really know why either it was a great show

ratings tanked when Earl went to jail - even though it was still pretty good

ratings tanked when Earl went to jail - even though it was still pretty good
That was their biggest mistake. I quit watching. I came back the following season but I guess others did not. It was a great show.

Unfortunately, I never saw even one episode until after the show had been cancelled. And I really felt like they had made a huge mistake...the show was fabulous!!

I believe the one cardinal sin the show made was similar to the failing of "Herman's Head". It required the viewer to think too much, to really get the humor.

Most viewers, IMO, like to be "hit in the face" with funny stuff that doesn't require them to sort out "why is this funny?"
It also might have hit just a little too close to home on the "white trash" aspect,.. for some viewers to acknowledge the humor.