Well, that's the exact reason why they wrote this page: to explain to people why they think GitHub is unethical, and maybe convince them. It's the same as calls

Well, that's the exact reason why they wrote this page: to explain to people why they think GitHub is unethical, and maybe convince them. It's the same as calls to boycott various other companies: they haven't necessarily done anything illegal, but if you convince enough people not to use their products/services anymore, you might make an impact...