If we're assessing the assholeyness of comments, yours aren't coming across all that favorably IMO, but perhaps this conversation is victim to the loss of context and inflection that other commenters have lamented.
I'm not sure how responding sarcastically is "fine." I've found that in real life, people don't respond well to sarcastic responses to ordinary conversation.
But if you respond like an asshole to a comment, it means you haven't learned the lessons you should have. IOW, the commenter is proving my point.