The reason for this is simple, some political views make people angry, some opinions overall make people angry. Like, if you really like something and then someone says that anyone who likes it is in someway bad, you're generally gonna get a bit angry about that and will sorta disregard them, cause it's an opinion. When someone says your identity is bad, or you do something bad, then it can make you feel angry of course, and so people may lash out. It's all about retribution, it's people being angry and lashing out emotionally, it isn't really a logical thing. If you've never felt the want to lash out at anyone, then it might just mean there's nothing you care about enough to lash out.
But, I always found that rehabilitation is a better and more constructive thing. See, people generally aren't really going to listen to adversary, when they see someone as an adversary agreeing with them means they lost, to their eyes, so they're less likely to agree. It's why heated arguments are so bad at convincing anyone of doing anything, we as humans have a pride, and we're so prideful we'd disregard things we'd normally regard in order to be victorious over our adversary. So what's the solution to this? Don't be adversarial!
This means discuss, follow debate etiquitte and, IMO, most importantly, don't argue with your logic, argue with their logic. One thing I've always found, ask a lot of questions about someones point of view. If you ask questions, you're generally not considered an adversary, you're considered to be curious and inquisitive, hey they may think they can convert you to their way of thinking by answering these questions and, hey, maybe they can! But more importantly, the more detailed your questions, the more you hone into potential problems, the harder it is for them to answer the questions confidently, the more likely they are able to see flaws. They are using their own logic and they're finding inconsistencies, things they don't know, things they can't respond to. Things that make them think, and that's what you want. You won't convert them in that conversation, but if you have consistent conversations like this (again not being antagonistic) and put the seed of doubt into their minds, that's when they become susceptable to change.
So in other words, you're right in that hostility does not make people change, in some cases it's counter productive, it makes people strengthen their original views. But the people who lash out aren't wanting that, they simply are angry, they have an emotional response because someone did something that emotionally affected them. They do not WANT those people to change, they just want to try to make people hurt. And while we can say this isn't the logical thing to do, because it isn't, it is an understandable thing to do. We've all done things our of emotion that have been counter productive, as humans we are imperfect, and anyone who says they've done something perfectly is lying (they may truly believe it themselves, but that's cognitive bias!). So yes, I'd support the idea of less rage against people with a different opinion (regardless of opinion) but I'd also be understanding in why there exists rage to start with.