Actually bitcoin miners are fucked.
Not quite. Or if so, then in a rather pleasant manner.
99% of the miners (paid in BTC) won't reach ROI ever !
But the majority of miners probably don't do their accounting in BTC. They probably do it in RMB or USD. In which case, the picture changes substantially.
They hoard the coins and wait for a price increase, otherwise they all lose money.
Only those who do their accounting in BTC. The true believers. And a large proportion of the true believers would mine at a loss, even in fiat accounting, just to support the network and stay involved in the protocol, keep their hand hot, awaiting new opportunities.
But yes, point taken, they will not ROI in BTC, most of them. Some will. Certainly mining new alt-coins is very lucrative, with GPUs, at present.
If the mining business collapses and 5000 coins are sold daily, there will be blood (candles)
That would be nice, but I wouldn't count on it. Mining has been this way since early 2013. No cracks are showing. The failures we've seen have just meant cheap mining hardware, in bankruptcy sales. The market for virgin coins is very brisk, and has been as long as I've been involved. Could change. No catalyst is evident however.
At the moment, only a few can win. Most can't cash out or they will lose money (market collapse). That's one of the main reason for the steady uptrend. It's not market adoption or increased utility. Transactions didn't increase very much the last 3 years. The price did with only a few percentage of bitcoins traded.
Transactions quintupled in 2012, tripled again in 2013. They will more than triple in 2014. But transaction count doesn't really impact BTC value directly. It's the volume that impacts value directly. Price and value not being equal, of course. A risk-free discounting of a minimum future valuation indicates that value is much higher than price at present.
I do agree that most miners will hoard in order to get break-even or better in fiat terms. I've been mining a while, and roughly 1/4 of my hardware has been negative in fiat terms at the time of mining but eventually positive with price changes, 1/2 has been positive in fiat at the time but negative in BTC, and 1/4 has been positive in BTC. Overall, it's fiat positive, roughly BTC neutral. When you do win, you tend to win big. But it is a terrible crapshoot, and I wouldn't recommend it to anyone who can't get a sweet deal on a hot chip at the right time unless, like me, you just want to keep a large exposure surface to the BTC universe, to keep your awareness keen.