What makes an appeal to experience, subjective or otherwise, an expression of Main Character Syndrome? Just because somebody pushes back against the tides doesn't mean they fancy themself more important than others. Further, they're not saying "we should all stop using LLMs". The title of the article is literally "Leave Me Behind", an expressed desire to no longer participate in a system they believe to be harmful.

They explicitly state a position they take for themself, whereas you make an implicit value judgement of all practitioners who feel similarly. This could be read in a way as an assumption that everyone else should be as miserable as you.