People have no problem with shows like 6Teens, Stoked, Total Drama Island, but they canceled Invader Zim?!?

Shows like Total Drama Island/Action, 6Teens, and Stoked are TV-PG. And theyre a lil racy. Once, on Stoked, this character was pantsed n his swim trunks fell, n they had this blur coverin his 'parts'. Wht gets me is that they let shows like THAT on TV, but they wont let IZ come back? Mayb its cuz of they r awn two different networks, but still...