Altcoins are now mostly dead to the threats/FUD about btc-e, and alt-coins were one of btc's biggest businesses. This represents yet another sector of the market leaving, like gox and China. Now people are selling their bitcoins instead of holding them on altcoin exchanges to trade altcoins and there is a reduced incoming interest into crypto as well.
When things look hopeless, and prices are down ~80 to 90% you have a perfect time to:
Buy, or give up and sell the rest off cheap?
maybe you can argue this point about Bitcoin, but I can't see how alt-coins can turn themselves around.
I have been preaching in the alt-coin forum many months ago that the growth rate is way too high and there is absolutely no way the prices can be sustained. To top it off all the alt-coins basically share the same investment money. Lets not forget about the miners who will all mine the most profitable coin to dump.
There is no solid case for optimism.
Two days ago I made over 100% in under 3 hours on a hopeless coin.
Those types of returns can keep me going for a while.