Earlier quoted context omitted.
I see your point but individuals living their sovereign lives isn't the issue; the issue is if Facebook keeps kindling the fires of division a day could come where we're knocking at the gates of a civil war. Is that too hyperbolic ? I don't know but if asking people in California what they think of Texas/Florida and vice-versa is a litmus test, perhaps some concern is in order.
The division seems to me leading more to a breakup of the united states, into smaller countries. If one believes in democracy, and local democratic will. Why would that necessarily be bad. The country is filled with red states on the inside, and blue states on the outside. Doesn't seem like the people in the middle are getting the kind of government they vote for. And the people in the blue states have to temper down…
But that kind of compromise is exactly what Facebook's algorithms are designed to ensure doesn't happen---nobody is gloriously excited about compromise.