It's natural that people would hang around others of a similar worldview. However, though, the anger and insanity that come about (in some) - when confronted with other views directly - seems to show evidence of a bubble.
I see it as a sign that people are increasingly taught what to think rather than how to think.
If you have learned how to think, analyse, consider different viewpoints and consider the merits/downsides of them, consider things from different perspectives, the chances are you will not only have an opinion on matters but also a reason why you believe what you do and the ability to articulate why you believe this over that. You'll probably also be able to see the merits in an opposing viewpoint, even as you consider your own viewpoint to be better because of some different set of merits (maybe there are more of them, maybe they have a greater value to you etc).
If you have been taught what to think the chances are you won't even know why you think it, only that you do. And because most people consider themselves to be reasonable people (let's face it, few people hold a viewpoint they know is unreasonable), it doesn't take a big step to assume that any reasonable person would agree with you. Ergo, anyone who disagrees must therefore be unreasonable and there's no need to even bother reasoning with them. If they can't see what is plainly obvious to you it follows they must be a retard/fascist/libtard/communist/traitor/whatever. Of course if the topic relates to specific triggers you get to throw around -ist and -phobic terms as a way to shut them down because naturally they shouldn't be allowed to speak if they are such a bigot.
It's natural to want to associate with "people like me" but if that reaches a stage where I don't associate with anyone unless they share my views on a wide range of social and political topics then it becomes unhealthy. For myself I find discussion with people who have a very different viewpoint is more enlightening than discussion with people who agree with me, as long as the discussion focuses on the topic and doesn't resort to insults.
A lot of the time a difference ends up being about what price someone is willing to pay for what benefits, and many times people are prone to overlook the price their preferred outcome demands. If something changes the chances are there will be some winners and some losers, so the question is as much about whether the number of losers is an acceptable price to pay (and what, if anything, could or should be done to mitigate the losses) as what benefit might go to the winners.
