Yes, this does end in fire.
Typically, these individuals people have quite unremarkable and moderate opinions, which they will go on to state in relative terms to one another, and then continue into what some would call a "full and frank exchange of views".
It often happens that these people's positions are markedly similar to one another's (though don't try to tell them that!). Now, of course there are real differences of opinion here, but they're typically obscured by the way they're stated. Mostly, we state things in relative terms, but apply them to differing baselines.
Give me leave to tell a little story.
Alice and Bob are arguing about
Alice says, "I think apples are too expensive."
Bob says, "Apples should cost something."
They aren't specific and never say, "I think the apple should be two dollars," (we'll say it's three right now) which they both believe.
Bob is arguing against people who think apples should be free, and paid for with fairy dust.
Alice is arguing against people who want to jack the price of the apple up even further, to line their fat Corporate greed holes.
But they both think they're arguing at each other.
Then, this cross talk will also obscure other, real issues. (Bob, for instance, thinks genetically modified apples may not be safe, whereas Alice believes that in this particular instance the modifications are well understood. Both of these positions will be discussed, not in terms of the actual information of them, but as part of a larger position into which both are walling the other into caricatures of.)
There are complicating factors. For instance, Carol, who things apples should be one fifty, and Dave who thinks apples are fine at their current price. But Bob feels like a dick with nothing to say if he can only say "Um, one-fifty is too cheap," so it requires him to "demonize" Carol, and portray her as the communist she's not. (And vice versa.)
And of course, don't forget Eve, who really does think three bucks is too cheap for an apple, and Fred, who doesn't really think apples should be free, but says he does because he likes being a dick.
Now... I'm sure that while reading this, you've realized, quite correctly, that there's nothing particularly Earth shattering about this revelation. But I've written it all down because the fascinating ability of humans to store information externally can give rise to interesting insights.
Sure, it's obvious that there are a lot of people out there that think different than you do. Equally obviously, these people are wrong. But the next time you become upset with someone, or even find yourself nodding along to what they're saying, take a minute to figure out whether those words mean what you think they do. With perspective, a lot of disagreements disappear.