RMS has seen (and likely started) more flamewars in his lifetime than most of us ever will. He has clearly developed (or adopted) a meta-system to deal with differing views. If you ever talk to a smart priest, it's the same playbook: when it comes to deep beliefs, there is no point hammering something in your face, because it won't stick. Either you get to "truth" out of your own reasoning, or it's not worth it.