Market fluctuates and everything is affected. Bitcoin drops does not mean it will continue to drop and wont hike gain, when this happens, maybe crypto world will vanish. Maybe altcoin season will now get higher price for those potential coins because it is the opportunity to altcoin to gain more value while bitcoin is dropping. Take this time as an opportunity to buy bitcoin because this is always the best coin and even institutions investing on it.
It is true that if the portfolio calculation tends to be more heavily charged on alltcoin it will be very risky when the Bitcoin price enters a major correction zone. but there is nothing wrong too, when you want to allocate 1/4 of the total portfolio into altcoins, with the implementation of a temporary trading system and return to the bitcoin path after making a profit from selling altcoins.