Is trading cryptocurrencies actually destroying their intended purpose?

Recently I became interested in cryptocurrencies and have started trading. I enjoy it. I'm doing it for fun, and I am being careful, emotionless, and trying to make a small amount of profit at a time.

But then I had a conversation with my father that has made me rethink the entire concept of trading them. Bitcoin and altcoins exist because they were intended to function as a new type of currency. However, because they are now being traded like commodities for the mere sake of making a profit, they are extremely volatile. It seems to me that as long as they remain extremely volatile, they will never actually be useful as currency. If that is the case, won't they eventually all crash? Or will people's interest in them as something to trade somehow keep them a float, while changing their purpose altogether.

This question is really, really, bothering me. Part of me says: shut up, make some money because you need it, and see what happens. The other part of me (and my father) says: stop trading these currencies and instead, spend them on real things, help to give them ACTUAL VALUE, and don't ruin a fantastic idea for the sake of profit.