I think we should actually hold until we can see bitcoin is stabilize and bitcoin price can be bring under control. For now the fluctuations is too high and there is no way some of the alternative coins can bear this preasure. I think one should hold altcoin's investment as you are definitely going to loss if you convert your bitcoin to altcoin. All the coins need bitcoin to survive but bitcoin did not need them to survive.
There are really good altcoins out there that are for long term hodl, like ETH. Right now bitcoin price will not stabilize or go to straight line because the sentiment is very bullish. But I don't think that the altcoin market is pressure with all the bitcoin run. Actually they hold as well, look at the top 5-10 coins and they have also enjoying a good run.
I somewhat disagree with the notion that altcoins needs bitcoin to survived, each altcoin is different project in my opinion and has its own "fan boys" just like bitcoin. I think they can survived all through out. They need each other mutually.