If you are doing this, how is it favoring you?
Some hardcore crypto miners in my state are into BTC mining for the past years now and I noticed that they don't mine in a bear market, they always buy their asic miners after Bitcoin halving or a month to Bitcoin mining and ride the miners through the bull market, and once Bitcoin start making a turn back in value they start selling their asic miners.
So, this is what happens behind the scenes: When bitcoin halving happens, reward gets divided by two, i.e. one day you were getting $1000, now you get $500. Bitcoin price doesn't increase or doubles overnight after halving, it's still a slow process. So, your miner, that was (barely) generating profit when reward was X, now, since the reward is X/2, it can't generate profit, it consumes electricity and your revenue becomes negative. During this time, some people sell their old mining equipments to collect money for new one and some people want to sell them as soon as possible. When this happens, people like the one you described above, takes an advantage of the market and buys old bitcoin miners in discount. Then, when prices increases, they start mining with these miners and generate some profit or some of them even resell them before the end of bull market.
I noticed that they don't mine in a bear market
Bitcoin mining is like, when more people mine, the higher the difficulty and opposite. So, during the bitcoin mining, if a lot of people shut down their miners, difficulty will decrease and it will be easier for the rest miners to get reward.