I'm a little bit aghast at all the comments saying this is normal or no big deal. Maybe it is normal (or at least common), but it shouldn't be. If you believe it's no big deal, I can't agree. I can see this kind of behaviour from adolescents, but adults should understand that words are meaningful and have consequences, and that even if you disagree with someone, they're still a human being who deserves some modicum o…
He was only quoting Tupac…
Using a reference with threatening language in it that is potentially unknown by the people recieving it, makes a death threat even more sinister as it feels like you're building in plausible deniability and trying to have your cake and eat it.
It's basically admitting "if I just said this it would cross a line, but if I quote it instead then it'll not cross a line for people who know it's a quote, but still cross the line for the people I'm threatening. So I get to make the threat and disclaim any intent at the same time.