You make a reasonable case. Still, context matters. It seems to me the OP was being emotional while the commenter was being snide, and the latter is more destructive.
Far be it from me on the day after Gore Vidal died to say that snideness is always a bad thing, but the community here is fragile and simply can't withstand the free flow of vitriol.
I do think that the author's post came off as somewhat precious. Saying Not compete with you, because you're a precious snow flake? was less polite than perhaps is ideal, but OTOH the author's post was also less-than-polite.
[1] "I didn’t want to believe your company would stoop this low. My mistake.", "rotten-to-the-core “platforms” like Facebook", etc