I do not understand what the alts are waiting for at all. When bitcoin goes up they go down because bitcoin is going up and their worth are pegged to dollar instead of bitcoin so their dollar value is either same or a bit less while their bitcoin value goes down a lot.
When bitcoin goes down they go down with it in dollar value as well for some reason while keeping the bitcoin value same. So with this logic whatever happens to bitcoin the eventual outcome is altcoins going down in price, what are they going to fall to zero dollars? That doesn't happen neither, sometimes all of a sudden out of nowhere altcoin prices start to go up, it is not because btc went up or down, it just happens without any reasoning at all. It is really hard to predict these things overall.
I do not think they will go to zero, you are only looking at it from the perspective of coins that are below top 100, what of the coins within the top 100, they are the ones that really have use case, and virtually all of those coins respond to bitcoin when it increases, same as they respond also when they decrease in value.
Remember also, that there is a time called altcoins seasons, and this is the time that most altcoins usually surge in price, although they all still depend on bitcoin too, because bitcoin will have to consolidate first before altcoins can start having their own bull run, and most of these altcoins that seems to you like they are zeroing will surely pick up, I think this should be best time to add some altcoins to our basket, especially ones that are still within the top 50 coins in the market.