That is true, South Park didn't push the limits as hard then as they do now.
I remember being in 7th grade, when South Park started getting slightly more vulgar. As such, I was allowed to watch South Park, but only if my mom watched it with me. Anytime something objectionable came up, we'd talk about it. As long as I could maturely take in what was going on and make the separation between fantasy and reality, everything was okay.