Trust me this is not exactly the case. The drop in the price of Bitcoin greatly affected altcoins. So you find a situation where alts that were bought at certain prices and because there was a drop in the price of BTC, the dollar doesn't reflect the amount it was bought
I guess it is quite impossible that the downfall of bitcoin will lead to the improvement of other coins, I guess it is the bitcoin that pulls the altcoins on the way up and it is quite having a direct relationship with altcoins.