My hot take. Apologies, but:
Why do people think they're walking AI detectors, soley based on the art itself?
I find it pretentious.
To be clear, the who, where, and how a piece is published is important context. One should be suspicious of suspicious artists.
But not the what.
Don't even look at the piece. Extreme cases aside, no one can definitively tell if art is AI generated just by looking at it.

Eh. I can live with internet paranoia.
But I’m disproportionally annoyed by posters who think they’re experts at something when they’re not. Especially so angrily/loudly, like the scenarios you point out.
It’s especially ironic in this case, as the “false confidence” AI gives is what the accusers are against, isn’t it?