Absolutely. For all the reasons mentioned already. You never know what's behind the next door so you have to think if Bitcoin crashed tomorrow, would you be okay? Any investor will tell you to have a diverse portfolio.
that's right, everyone knows bitcoin has a high risk. so don't ever put all the money in one basket. Although it looks very profitable but we also have to think about a loss. because bitcoin price is not always increase.
I accept you.You can inverse 50% in Bitcoin and remaining 50% in various altcoin which you thought it as Best.Their are some Altcoin like ETH ,Lite coin and Waves,Which are as best as Bitcoin .If you want money means,you can sell Altcoin when the price of Bitcoin is low.