Altcoin prices dropping as bitcoin prices decrease is fundamental. This is the process of cutting the investor's double hole: D
It is not that bad but yes, altcoins are always depending on bitcoin for their increase and decrease. Who are investing into altcoins are still somehow depending on bitcoin for their good retunes. This is the reason people prefer keeping both the master and the slave. It is a great combination for long term investments and trading at the same time. I am in favor of investing equally in both coins.