I must say, my facebook timeline is nothing like people on here describe theirs. Mine is full of decent, reasonable people. I have a few brexiteer friends, we disagree on that issue but otherwise they're decent sorts whose opinion I don't happen to share and that's fine.
But the minute anyone starts spouting or sharing racist/anti-foreigner crap, they're gone. My life is just too short to read such nonsense every day. I wouldn't sit with such people in a bar, so why would I do it online? As a result I only interact with people with whom I'd happily share a couple of drinks. Apologies if any of this sounds snobbish or condescending, it's really not meant to, but I have found that life is so much nicer when you surround yourself with nice people.