Altcoin prices are tightly linked to bitcoin prices. one can easily say that whenever bitcoin goes down altcoins also go down but same cannot be said for the reverse. We have seen that btc recovery is faster than alts. Since more than half of the current market money is invested in bitcoin only so due to its stake in market it brings down the whole market alongwith it.
I, too, can not understand such a tendency to react differently to the rise or fall in the price of Bitcoin. If the market falls, then prices fall all together, And if the price of Bitcoin is restored, other crypto-currencies move reluctantly.