It's not ad hominem, it's just that Hacker News is often so (quite rightly, in my view) focused on growth of private industry and tech start-ups. It seems bizarre a Marxist forum crops up, with seemingly swarms of support.

I don't see "swarms of support". I see informed debate and discussion, which is a breath of fresh air compared to the knee-jerk reactionism usually associated with the topic.

And it's the same kind of reactionism that you're illustrating all too perfectly.