Crypto market is highly volatile, but there is never a bad time to invest 
Investing usually depends on holding, as the longer you hold your holding the more profitable you will be but this should be on Bitcoin. Bitcoin is the only investment that is extremely low risk, yet with high risk, ordinary investors tend to invest more in Altcoins. So if one wants to invest then it is best to invest in bitcoin because bitcoin investment can get maximum profit but after holding for a long time.
Bitcoin is stability, alts - potential at hand.
Everybody decides for themselves what suits them best, but I agree with you - both are viable for their appropriate goals.