@adamgreenfield Because RMS is known for not being exactly good at social interactions and he would have probably appreciated being told that he was being an asshole instead of being badmouthed on the Internet some time later?
Because @f4grx could have misinterpreted his intention when he told him to speak louder? Maybe RMS felt that he was being shy and wanted (misguidedly) to help him open up? (Think of the improvised poem scene in _Dead Poets Society_.)
Because understanding the other person's point of view would help him avoid these situations in the future and give him some closure?
I can think of more reasons, but I'm tired of typing the obvious.