Stallman is a good extreme, in that he creates and lives by an idealized system (call it "pure" if you want), which enables a lot of less ideal, more real-life

Stallman is a good extreme, in that he creates and lives by an idealized system (call it "pure" if you want), which enables a lot of less ideal, more real-life versions to exist in between his and the "commercial software" world, without any negative side-effect to the world at large.