It's not difficult to say, but it can be difficult to live at any meaningful scale. That invites endless pressure campaigns and similarly endless accusations of acting arbitrarily, capriciously, or with insert-bias-or-agenda-here. None of those are free to handle in any responsible or timely fashion. Never mind what happens should a genuine mistake be made.

It puts the company in the same position as Facebook in regards to moderation. It's endless, expensive, and your work is never good enough. Not a desirable position for most.