@jonhammack I think you can feel entitled to a reasonable, polite response, even if not necessarily a handshake. For example "I don't want to shake your hand because I'm not comfortable with it, thanks for the games" is declining a handshake, but nobody should get mad about that.
Handshaking really doesn't make sense anyway, it was originally meant as a sign of peace because you couldn't draw a weapon. As nerds we are resistant to change and must accept the original meaning of the handshake. The opponents are "battling" so there really is no need for a sign of peace, I would prefer waving a white flag or giving your opponent the pick of your best livestock.