I don't know if crypto currency's volatility is the main sellibg point that we should advertise. I mean yeah it helps alot if we're treating it as an investment only, butnthe goal here is for adoption. So the main selling point should be the next big thing in currency because it is instantaneous and is decentralized.
The volatility of the cryptocurrencies let people make money. The difference between the prices of one altcoin (or Bitcoin) gives a trader a chance to earn a lot. Volatility feeds him.