Because fundamentally it's the same type of censorship as someone deciding to not sell porn magazines, videos or the the Anarchist Cookbook in their newsstand/bookstore/etc. back in the day. They judged (probably quite rightly) that it's not good for business.
Of course the market being extremely concentrated and effectively an oligopoly even in the best case does shine a somewhat different light on it. Until/unless open models catch up both quality and accessibility wise.
Of course the market being extremely concentrated and effectively an oligopoly even in the best case does shine a somewhat different light on it. Until/unless open models catch up both quality and accessibility wise.