It was part of the original Sunday lineup of Nicktoons! Along with Doug and Rugrats. Ahhh Real Monsters and Rocko's Modern Life joined them a few years later. They syndicated and moved R&S around quite a bit, probably trying to make their money back on it or find a timeslot it fit into well. It moving to late nights and other channels with the much later Adult Animation Show did confuse the issue for many people, but I assure you it used to come on weekend mornings and was a trip to live through. You'd finish watching the wholesome adventures of a band of babies, and then in under 10 minutes a man made of toast is shoving cats between his buttcheeks.
It really is astounding that John Kricfalusi isn't in jail and stayed working for so long.