I have deiversified since the beginning.
It is never smart to hold all your eggs in one basket. Regarding crypto this means it is spread across several altcoins I think are promising. In general, this means I also hold a normal savings account and an investment account for stocks and investment funds.
I hold
gold as my "alt-investment". Hear you re diversification.
So far I have not decided to hold any Altcoins because I have not had the inclination to go look at any. My feelings may change if the BTC Civil War keeps going on.
To be honest I don't think that any specific alts are reliable enough to warrant a serious investment. There's Ethereum but that's pretty centralised and I'm not sure I would trust that people would use it who are techy or clever Bitcoin users.