Yup, the altruism is just spin.
Musk got what he needed out of the patent system. Now that it poses an obstacle to him ...
Actually, Musk would be more useful to creating a healthier economy if he made it clear that he was NOT being altruistic. Far better that he demonstrate that government-protected productivity dampening is a lose-lose all around, and make clear that he intends to profit off of releasing the patents.