Because he’s an asshole

Facebook knows that it is poisoning political discourse, it could take steps to ameliorate the situation, but refuses to because it would make Republicans mad:

That presentation went to the heart of a question dogging Facebook almost since its founding: Does its platform aggravate polarization and tribal behavior?

The answer it found, in some cases, was yes.

Facebook had kicked off an internal effort to understand how its platform shaped user behavior and how the company might address potential harms. Chief Executive Mark Zuckerberg had in public and private expressed concern about “sensationalism and polarization.”

But in the end, Facebook’s interest was fleeting. Mr. Zuckerberg and other senior executives largely shelved the basic research, according to previously unreported internal documents and people familiar with the effort, and weakened or blocked efforts to apply its conclusions to Facebook products.

Facebook policy chief Joel Kaplan, who played a central role in vetting proposed changes, argued at the time that efforts to make conversations on the platform more civil were “paternalistic,” said people familiar with his comments.

Another concern, they and others said, was that some proposed changes would have disproportionately affected conservative users and publishers, at a time when the company faced accusations from the right of political bias.

It is, to put it mildly, not a coincidence that Kaplan was George W. Bush’s Chief of Staff. Facebook simply decided to agree to aid Republican ratfucking efforts (while also making its user experience worse) in order to protect its profits from the kind of retaliation from Trump Jeff Bezos is getting because he’s letting his newspaper be a newspaper.