It started quite a bit ago. Probably with some of the first arguements between humans. So, there's nothing strange about how humans interact with each other when they disagree. Where there is strangness is that unlike the days when ignornance, hatred, lack of facts, overheated emotions, and bull shit used to be called out for what they were, or dismissed by those who knew better, the currency of debating or arguing points now rises and falls with how well the individuals ignore reason and rely on the things listed above.
Our culture these days seems to reward those who are good at ignoring facts and rationality. Nuance? Forget about that. There's just no room for something that requires any degree of nuance. Yell loud enough and you win. Insult the other side and watch the arguement spin uncontrollably away from the topic at hand.
Again, this has gone on for as long as humans have argued. But it has developed into such a science and such acceptable behavior these days that we don't argue anymore, we just lob words and emotion back and forth and walk away like some gorilla roaring out loud after marking his territory. Would that be evolution or devolution? I don't think it was any part of anyone's Intelligent Design.
Sure, this shows up in our politics (there was never much room for rationality there in the first place), and it shows up in arguing about which gadget is better. It shows up in reviews of all sorts of products online, and when it comes to religion, well, we've been waging wars supposedly about that topic as long as we've been able to wage war. Watching this occur over topics that involve any mention of science has become almost like watching a Road Runner cartoon. Only problem is the coyotes are winning because they make more noise more efficiently.
There used to be a day when the art of the orator or the actor required one to have a big resonating voice in order to be heard. Well, in both instances, now that technology has allowed those with quiet voices to be heard, being loud doesn't count for much anymore in those fields when it comes to getting ahead. The tiniest voices can be amplified and modified, often masking the tiniest brains and the tinest of talents. The difference, these days, isn't about how much sound you can produce, it is about how much noise you can make without saying anything of substance regarding the point at hand.