When you trace the boundaries of these media products over and over, you will eventually reveal and map the explicit guiding principles of the people in charge. At some point, the feminists in control of Star Wars, Star Trek, Marvel, and DC wrote down their priorities on a literal white board. They created rules to govern their “creative” output. All South Park did was suss out and accurately translate those rules. It “keeps happening” because it’s not a joke. It’s literally policy.