Funnily enough OP could give you no answer. It seems they just spewed without thought some of the anti-union propaganda that is so common in the US. And nowadays in Europe too, sadly.
TBF, there's not really a notification mechanism for comment replies in HN, so if you're like me, and you just occasionally check in on your comments, it's easy to miss responses until ridiculously too late. I know I have done this in the past.