"AI slop" was first used in academic world, long before "AI" or "slop" even existed as terms. Then it was just called "machine-generated". Like, I'm talking about 10 years ago or something! And it was much MUCH worse than the current LLM/ChatGPT crap, to the point it didn't trick anyone, everyone fully understood what it is, and yet it existed.
It's because academy is largely a system that exists to control money flows. Some pretending needs to happen, fake artifacts need to be created in the process. Humans obviously want to automate this work, just like sending Viagra emails was automated over 25 years ago.
There are some 50000 universities in the world. Probably 500 of them are actually very good, or somethig. That's 1%. Next 9% probably try to do their best. Rest are basically just scams.