Well if I'm a miner too I will also shut down my rigs, why?
First of all as you can see the market and the Bitcoins price it's dropping nonstop. You have invested to buy equipments, paying electricity and maintenance of the equipment just to mine a coin that the price is dropping isn't? Let's say you pay for electricity as well as the equipment for $1000 and you're going to sell the Bitcoin you've mined just for 300$.
if the price of bitcoin can be better in the future, that means we can get more money if we sell at the right price and time
maybe now the price of BTC is dropping, but who knows what will happen in the next few years?
and what happens when the BTC allocation to the mine is up? can fly high to the moon, and the worst possibility is to fall to the bottom of the trough
all of this is only based on the beliefs of each miner