Mining is no big deal issue. Half of all miners loose money. The difficulty will simply drop. It's happened before.
No! Why should the hashrate drop? Because they want to lose even more money?
Successful miners mine at a loss 90% of the time. That last 10% of the time, they make 20X% profits. That's the way it works. It's the long game. The smart ones lock in operating expenses for years or donate to the Cause knowingly. The WANT difficulty to rise to the point that only they can continue to mine at all, much less mine profitably. Then they have cornered the market. It's not different incentive-wise to me wanting to die with the most coins.
Personally, when I wear my miner hat, I do not consider the fiat price of bitcoin at all. I consider mining as my second job, and I concern myself only with acquiring more coins. Those coins I expect to be my retirement fund.
(I must admit that I did not always feel this way, and sold more coins at sub ten dollar prices than I care to think about. My philosophy at that time was that I had to pay off my investment, $2600 for 4 7970's - sold at least 3 or 4 hundred coins just to pay those off. Since ASICs all my hardware purchases have been denominated in bitcoin. When I make a decision whether to buy new equipment or not, it is based solely on the amount of bitcoin the unit will cost, and the amount of bitcoin I expect it to mine, within a reasonable amount of time.)
Only when I wear my speculation dunce-cap do I worry about price.
