I don't know what to say. Someone went to a person who is well known to have the position that nonfree software is unethical and to be an idealist to ask how to make nonfree software and somehow is surprised that the answer is that they shouldn't make nonfree software.

I would expect the same if I asked any particularly idealistic vegan how to eat meat with less impact. The idealistic vegan will just tell me to not eat any meat.

Also, in no way is any of what I said contingent on Stallman being an asshole, but it also surprises me that someone thinks finding Stallman to be an asshole at all surprising. He is a man of strong convictions that won't budge, and it's easy to find many anecdotes where people paint him as assholish.