I never believed that altcoins are in dying stage, because first of all crypto currency now are starting to become famous in many country. So I'm sure that altcoins have a huge chance to increase their value on the following weeks or months, all we need to do for now is to be patience waiting for the right time.
Moreover I think if the alternative coins are dying, balanced of crypto currency will be destroy. The possibility to increase bitcoin are higher but the in return they can't be afford this coin in the future.
As you said the bitcoins are not dying the price just fell sue to the huge demand for bitcoin but in the coming days the price of ethereum will start to rise because many people got the knowledge of crypto currency so new investor will come in the near future.So it is good time to buy altcoins because the price of most altcoisn are cheaper so people who is looking for long term investment will pick their coin now foe cheap price.