The person who replied to him basically just said, "I disagree." They didn't provide any reasons for this. They were also being rude. I think his response was appropriate.

When you're factually wrong, there's not much to say other than "you're wrong and this is why." When you get saucy about being wrong...

But you didn't provide the "why" part. And he wasn't being saucy at first. He only did that after you didn't say why you disagreed.

I totally provided "why." The public domain has nothing to do with open source. Copyright doesn't apply to brand use. Dude didn't research but hopped right up on that soap box, and judging from the upvotes, I wasn't the only one to be put off by it.

You didn't say that in the reply that he responded to.