I think its mostly due to BTC prices and troubles in china with some exchanges. Miners get scared and start to sell their coins to try and not loose money.
ZEC has a long way to go and until its off to the races its hardly tied to BTC and its bullishness. And yes the ZEC prices go down, but with miners switches to PASC and difficulty reducing you get more ZEC’s on a day averaging out on your daily returns (based on my own big farm).
So there is no crisis, except people hyping a problem thats not there making the price drop and them buying ZEC’s cheap. I think most of the poeple have consensus that ZEC will take off (probebly Q3/Q4) and heading to the 70-80$ region, perhaps even 100$ if the Z-address payments are adopted (incl. into ETH).
So as a miner you shouldn’t be scared and sell all your coins. Just sell the coins you need for rent & power and keep te rest for now, its gonna be worth it in the long haul.