For some reason, Seth MacFarlane isn't well liked by other animators. Groening's been very uncomplimentary when asked about Family Guy. Matt & Trey, well, you saw their barbs last night. (Stone once said in an interview when people compare South Park to FG, it's like kicking him in the groin.) Even Kevin Smith took a shot at him in the first half dozen episodes of the "Clerks" animated series.
I wonder what Mike Judge thinks of him? I know he and Parker and Stone seem to get along.