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.
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.
