This is particularly important when a thread is fresh because threads are so sensitive to initial conditions.
Questioning that there's a homeless crisis when the data shown in the submission states that there's north of 500,000 homeless in the US is an absurd starting point for a conversation.
That is, _there is no conversation to be had about that question_. And any debate held by HN on that would be astoundingly privileged.
Of course, if you had posted a substantive comment about homelessness in response to specific things in the article, that would have been fine. That's very much not what you posted.
As for "there is no conversation to be had"—this is the sort of categorical putdown that tends to go along with unsubstantive posts in the first place. Would you mind reviewing the site guidelines? We're looking for curious conversation here, not position-hammering. There's a big difference between those, even if all of your views are 100% correct. Launching straight into a flamewar when the thread is brand new is definitely not the intended use of this site.
Surely it isn't hard to understand that "Yes. Yes there is." is an unsubstantive comment. This is not a borderline call.
What dang does know is that, by HN standards, chrsig's answer was pretty useless. He's asking chrsig to do better, not to have a different answer.