Use your head once in a while! When Bitcoin was in the bear market of 2016 with prices below 4000 miners were also below the point of profitability with no way to pay off equipment bought in 2014 for $600 and more. Did that destroy Bitcoin? Even if we repeat 2015 and 16 worst thing that can happen is another 6 months of bear market and maybe 4000 dollar low
That's true, they trusted the potential of bitcoin and waited it to boom but if we're looking at the current state there is so many coins that has been keeping up and new coins coming in, the fact that bitcoin is replaceable after all there is a chance that because of the electricity and mining rig being expensive more and more are considering other option and that is one thing that threatens bitcoin at the moment. It depends on the miner or users view to be loyal and consistent or to try other ways in difference.