No.. It is unfair to use "only" because crypto (bitcoin in this case) really offers faster transaction and other practical features for us. I think the word "mainly" is more appropriate . Well, I am not a hypocrite do deny that lol. I also harness btc's volatile price to earn money. But even though we are a little bit shifting into main vision of btc, for me there's still nothing wrong about it because the opportunity of earning was already there so tendency everyone will definitely take advantage of it. Plus, there's no rule saying that we cannot use it for trading thus no need to feel guilty at all.