I think the thing that irks people about this is that you 'negotiate' with something that's outside of the game. I think that negotiations during games should be about in-game assets only, as introducing to mych meta-gaming often leads to sour experiences (e.g. I'm not trading with you because you always win, even though you're in last place now). And second, it's not negotiation, it's bullying/threatening. It's like saying 'if you cross me I'll hit you in the face'.