>>101504553>a 8-season mainstayRegular Show hasn't had prominence on the network since Season 5, they stopped promoting it during Season 7 and some of 8. I really don't think they saw it as a mainstay and more just baggage. Both AT and RS don't have the network icon image anymore, CN doesn't give two shits about them.
If they had had real reruns, promotions, etc. I'd see the whole mainstay argument, but they really didn't see them in that light, and were trying their best to make everyone forget it existed.