Altcoins are anything but independant of BTC. The recent slump is to be expected when BTC falls upon hard times in the public eye - less speculators with faith in BTC means even less speculators buying up cheap altcoins.  Scrypt ASICs from gridseed are also playing part, very likely.

If your power is expensive, scrypt mining with GPUs may soon be (or already be) unprofitable for you.  Such is reality.