Sure I'm going to invest my retirement savings in a volatile, unregulated, digital crypto-currency that isn't even quantum proof. \s Hell the core developers can't even increase the transaction block size limit to save their lives. If I wanted to take a stupid gamble I'd just do it here in Vegas.
Financial theory says that in order to have balanced and diversified portfolio (and not to have all your eggs in 1 basket) it may be a good idea to have up to 10% of your assets in more risky things with growth potential.