So, the question is really about adoption. How do we expect cryptocurrencies to be adopted as valid payment methods when everyone is really using them as investment stocks? Will we only see proper adoption once the current greed and "quick buck" mentality subsides?
It goes back to volume. Even if crypto is used for speculation, as the volume of trade increases, the volatility will decrease. When trading volumes are about 100 times what they are now, the volatility will be depressed enough for crypto to be used as actual currencies.