"You" did not refer to a generation, but to a person, so the language was personally insulting. The bar for personal insult is much higher and this comment doesn't pass it. First, the OP did nothing to deserve it, so it was out of place. Second, delete the insulting language and the comment not only doesn't lose information, its point (defending Facebook) becomes clearer. There was no need for arbitrary sticks in the eye. That's the meaning of "gratuitously rude".
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.
 "I didn’t want to believe your company would stoop this low. My mistake.", "rotten-to-the-core “platforms” like Facebook", etc
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.
This argument has been made for likely as long as the human race has existed and is completely worthless. May as well say you walked up hill both ways through snow on your way to school every day.
And you try and tell the young people of today that, they won't believe you.