The diagnosis of some psychological problem solely based on the fact that he won't agree to follow the arbitrary established order which is against his convictions is a common feature of authoritarian regimes.
The accusation that if he disagrees with a system of laws because he wants them to be more ethical and less ambiguous he is undermining a social construct that is needed to keep society "humane" is worse.
It's not helpful, when someone disagrees with a law or set of laws, to argue against the entire concept of disagreement with law - unless you want to either paint them as an absolutist or an anarchist. Psychological problems are usually diagnosed based on the amount of suffering of the individual, and RMS doesn't seem to be suffering at all. He has specific concerns that can be replied to specifically.