I don't think that's what the author is saying. The argument seems to boil down to "using oversimplified language does not get your point across as effectively, because words mean different things to different people". Its a linguistics essay rather than commentary on whether LLMs are good or bad
The author wants people to say "ban all generative content" or "ban bad generative content" because "ban slop" could mean both depending on who's talking.
This bit for example, for where AI tech marketing also uses the term:
One attitude “AI slop” can express is an attitude of quarantine. In this use, the slop is seen as unfortunate and not representative. To call it “slop” is to try to cordon it off from the good stuff that AI can produce, the useful translation, the genuinely helpful code, or the new mathematical discovery3. This is how Sam Altman used the term when OpenAI launched Sora 2. Creativity, he wrote, could be headed for “a Cambrian explosion,” while the “RL-optimized slop feed” was a degenerate case they put great care into avoiding4. It is also the attitude Google tried to take when its AI search suggested using glue to keep cheese on pizza. The company said such results came from uncommon queries5. The embarrassing case was sealed off so the rollout could go on.