Why should anyone care at this point? They're just trying to acquire attention and remain relevant, especially when they're never getting on the big international stage (NRG).
I don't see anything wrong with him making a joke, people can still say what they want to say and joke about situations. Trying to remove that freedom with threats will not work on people from free countries, it will always backfire.
What bothers me is that people say we should take death threats very seriously...and then procceed to make jokes about it (not even counting adding fuel to the flame which is happening here). Is it the best approach? Cheers.