Stallman is a "prophet": he needs to be extreme and rigid in his ideology so that the world shifts to a more moderate middle ground. For GNU to actually change the world, they need to be a pole of extreme that is opposite to our status quo of capitalist consumption. You are not supposed to emulate him.

You see this phenomenon in every movement for societal change. The more dogmatic they are, the larger their effect on public opinion.

The fact that the modern programming world defaults to releasing their code using corporate-friendly OSS licences like MIT is thanks to Stallman's and GNU's campaigns.