Things in society don’t exist in a vacuum, and “who cares about them, so long as I get my needs” is quite literally a part of the problem being discussed.
As someone with a GLP-1 user at home, responsibly depositing their syringes in an approved container that we dispose of safely at a drop site, I'd rather not have bad users inhibit my access to a tool that makes our lives better.
Just because things do not exist in a vacuum doesn't mean they should be blurred and conflated until unrecognizability. There's value in explicitly anchoring the salient aspects, and getting the cause and effect right, to the extent these can be done.
Both intelligence amplification and pathological parasocialness are very real effects of this technology, and a blanket ban, a blanket halt, and similar broad and dull policies are absolutely going to be unfair and unreasonable. And even such policies would not "happen in a vacuum", there's a consequence to prohibiting something not prohibited elsewhere.
Whether we can do better is where the jury is still out. I don't think an example like your dirty needles one particularly helps with this. It's asinine and inflammatory, quite the opposite to nuance-inviting, which I believe was more towards your actual intent.