I'm humbled and so happy you took the time to comment, even more so that you did so three times. Definitely nothing to apologise for. I've enjoyed the insight into what drew your attention and loved reading your thoughts.
Your pet peeve is so on point! I don't get it either. Someone puts thought and effort into engaging with you, I feel the least you could do is say hi and thank you. I find it off putting, too. Makes me think, maybe get off the high horse and have a casual chat with the masses over here. And you're right, I too feel it's closely related to one's inability to have a polite debate. That baffles me as well. Who are these people writing for and why do they do it? It's obviously not to engage with readers or to exchange opinions and forward the conversation around the topics they're passionate about. Do they simply want a fan club, rather than actual readers?