Strongly agree.

I'm not advocating anything like "always respond". I'm advocating that when people actually think it's a strong critique, they should respond rather than playing the status game of pretending they don't really think it's a strong critique by ignoring it. Additionally, even if they don't think it's a strong critique, if many other people 'whose judgment they would trust in other similar situations' do think it's a strong critique, then they should also respond.