I love commenting on other writers' stories. I read the story carefully, and I only comment if I think I have something of value to add. I craft my comments carefully, and it's not unusual for my comments to get more fans (sometimes 100+) than my articles.

If I disagree with what a writer says, I'll make my point respectfully. If I think they're totally off base, I just leave no claps or comments.

Responding to comments on my own stories is IMO an obligation, though sometimes my response is crashing silence. I have gotten a few of the ones like you describe, who want to wander off on their own tangents, post links to marginally related stories, or draw me into extended discussions. So far I haven't found it necessary to block any of them, but if they'd been as rude as the ones you've encountered, I'd definitely do it.