But I'm not convinced it's fear. It feels more like overconfidence that they know what's Right. And if one is so sure something is correct, why would the other side need a say? Particularly if it's offensive or potentially hurtful to friends? They are likely to believe it's being said TO offend, rather than add value to the conversation.
I remember feeling very certain of many things when I was younger (marriage is for men and women, for one), but I didn't have social media or the ability to wrap myself in an echo chamber or bubble. I had a very outspoken family, and wotmania, aka: every opinion any kind of person has ever had in one place. I almost can't remember the original me.
I can empathize with how you perceive yourself to have changed. I too have changed. I used to be a militant atheist (Soviet parents, NYC raised) and now am much more accepting of religions, especially the good influence of Christianity. Yes, no religion is perfect but there are so many good people who practice religions that I can't be them anymore. People at Wotmania helped me become a better person; a more open minded person.
I do wonder if those echo chambers are part of the problem. We only see a part of the world rather than the entire world. We can choose our news. We can then choose our friends. We can do so much choosing that when we see a part of the world we think its the entire world. And so when we see glimpses of the worlds outside our bubble we are shocked react negatively. Perhaps it is fear of the unknown. Perhaps its a lack of tolerance. Perhaps its all those issues together to combine together to create the problem.
But as long as there we accept that there may be a problem and talk about it then we can at least think about ways forward that fix the issues.