Richard Stallman is nuts. Here's why.

Not really. He might be defending his position with the same zeal that others defend their religion (it's difficult not to be zealous about something for which you have made important sacrifices), but there is a huge difference.

Religions have questionable basis and use: it is both impossible to prove they are objectively true (at least through the scientific method, the only way we currently have to discover what is true) and to claim that they offer something valuable, which could not exist otherwise, to a human society.

Software freedom (or lack thereof) on the other hand has objective, practical consequences. They might not be direct, or apparent, or significant for every user in every possible use-case, but it is rather easy for a semi computer-literate person to understand that they exist and that they can be pretty negative and serious in too many cases.