Because a lot of people who hear that take it as literal encouragement. The events of Jan 6 are one example of how threats like that aren't simply rhetorical devices.
The real question is why are people incapable of regulating their own behaviour. It's convenient to say that talking about hanging politicians encourages this behaviour, and contributes to it
End of the day though -- why should my speech be held as responsible for another persons conduct?
Yeah, I just asked a question. When? I'm not asking anyone to do it. I don't really want anyone to do it. I'm comfortable. But I do suspect it may happen soon.
Unfortunately, personal responsibility has gone down the absolute shitter in the USA, hence why they are limiting our liberties - those only work in a society of nice people.
Because a lot of people who hear that take it as literal encouragement. The events of Jan 6 are one example of how threats like that aren't simply rhetorical devices.