Facebook isn't a neutral arbiter, they make active choices in what their users see. And they frequently choose things that maximize engagement in order to maxi

Facebook isn't a neutral arbiter, they make active choices in what their users see. And they frequently choose things that maximize engagement in order to maximize profit. Things that are inflammatory and divisive drive engagement, so that tends to bubble to the top. This isn't just a problem with Facebook and Twitter either, its an issue in modern journalism as well. Basically anything that is funded by advertisement will fall into this trap.