Actually I disagree here. I'm grateful that the founder of all people actually took the time to respond. This show's that they care what their users think.
It wasn't the response that was being objected to, it was a (polite) suggestion that the rudeness of the response is not good marketing.
Nowhere does the replier suggest that the founder shouldn't respond at all, they are simply suggesting that a friendlier tone will look better than an unfriendly one.
See also: the old story about catching more flies with honey than vinegar etc.
What you did instead was insult them back and now you can be sure they will not have anything nice to say about your company. To do it on a place like Hacker News is quite shortsighted since you never know who you're talking to or who is reading your posts.
Erm, shouldn't this go both ways? Like, isn't this equally applicable to posting snarky, uninformed comments in the first place? :)
Therefore, the most useful advice is that given to someone with something to lose. Whoever was "wrong first" is irrelevant to the outcome desired by curiousoffice.
Agree with your general point.