It's a sophist play on emotions. I don't think there's actual malice behind it, though. More that people struggle to assert themselves and provide direct, well-reasoned arguments. So, exaggerating or throwing meaning away altogether is an easy alternative. It is also particularly useful in obscuring a lack of any sort of coherent plan or proposed action(s) when one is angry/frustrated/etc.

To some extent I also believe it's natural to try to elicit an emotional response from the other "side," because then you can focus on attacking their words, tone, character, etc instead of engaging in reasoned discourse and debate. You get a bit of an automatic advantage if your opponent is already in an emotionally charged state. From what I've seen, the phrases you mention are pretty good at that too.

All of this ends up doing more harm than good most, if not all, of the time.