Don't randomly start insulting someone just because you are wrong/ran out of arguments. I'm here for a civil conversation and you should be too.
I think a large part of the problem there is when people have been taught what to think rather than how to think.
If I think what I've always been taught to think by people who I trust and who are reasonable then what I think is reasonable, as any reasonable person would think it. Since I'm a reasonable person anything I think is reasonable because if it wasn't I'd think something else, what with me being reasonable and rational and all that good stuff.
Then you come along thinking something else. Clearly you aren't a reasonable person or you'd think the same as I think. You clearly aren't a rational person either, or you'd think what I think (since I'm both reasonable and rational). Therefore you must be wrong and not only are you wrong you must be irrational to not see how very wrong you are.
(Of course, if you've also been taught what to think rather than how to think, from your position the same applies in reverse).
In the absence of an ability to think and consider whether your viewpoint might have some merit, whether - horror - my viewpoint might be wrong, whether we might be in a situation where we could both have valid viewpoints, about all there is left to do is either go away (and arguably be seen to be admitting defeat) or double down and throw insults at the person who is obviously so wrong and so irrational they can't even see it.