Think about it again. A lot of data shows that if you invest the same money in buying bitcoin, you can earn more than mining it
Yeah I agree, I mine BTC because of rentability. If BTC drops, I will keep my rigs powered off, and power on them when BTC will be higher.
And your reasoning doesn't take in consideration solo miners : if you have enough power to be able to solve blocks sometimes, you will earn more than you can ever invest in general. Take in consideration the fact that the ASICS doesn't lose value with time (when they are able to work), it depends of the BTC value.
So the magical formule could be : buy cheap asics when bitcoin drops, mine, and when bitcoin increase a lot, sell them. You will have BTC for the price of electricity, with free (and some beneficits) asics. In my case it works great ! (I personnaly don't pay my electricity at a high price, I know that this formule doesn't works for everyone)