This is not even something to argue about. when you gamble and you lose which mostly happens then your money is gone, but when you invest in bitcoin even if the price drops and you can hodl with patience then once the its back up you wont lose and also have increase in dollar value. its not easy to win such an argument with someone that is an addict especially. maybe they are thinking that its all risk which i agree even life itself is so full of risk but when it comes to BTC investment then it can be compared to gambling.  for me i would just let it slide anytime such argument comes up.