I've blocked, or unfriended, several people over the past few years.

New mothers that think it's awesome to send out picture after picture, and post after post, about their new babies get blocked for a few years. I check in occasionally to see if they've stopped. If they have, the are unblocked. If not, they stay blocked.

If someone is just spouting close-minded nonsense, they get unfriended. If someone is only posting about how much they partied the night before, they get unfriended. If someone has a bunch of self-induced problems, and only wants a pity-party, they get unfriended.

I don't really care who they are. I've unfriended or blocked close friends, and I'm about to block my brother-in-law. If they notice, and ask why, I'll tell them why. Just because someone can post something, it doesn't mean I have to read their unending fingervomit.