It's hard to want to be friends with someone that might support the abolishment of something you like, or that supports something you should feel abolished (does it matter which?). It's still possible, but I've found that I eventually figure out where someone stands on something and gravitate away from them, even without social media. Ultimately one of the biggest problems is the total lack of civil discourse. If that was more prevalent, I think it would be easier to have friends with opposing views. Nowadays, people throw up their arms and accuse you of being X when they can't articulately argue a position. That gets tiring.
As the article mentions, in some cases, social media reveals the depths of someone's political positions, personal beliefs, or other that you might not have known. Is it worse to know those things, versus not know? Hard to say, but I personally like to have things in common with my friends. There are no easy answers here, so my personal solution was dumping most social media, like Facebook and Instagram. I hate Twitter, but find myself having to use it to keep up with news in the infosec community; even if the group on Twitter is an echo-chamber club that mostly uses their "status" in the community to influence on topics other than cyber (super annoying).
All I know is, my peace of mind seems to be much better without social media; I don't miss it at all.
[edit] spelling correction