Keep in mind you're looking at this like an investor and rightly so you won't profit true.
But entrepreneurs take risks too I'm only highlighting the situation that a bad investment will still never ROI but continue to support Bitcoin by mining.
I don't think many miners will continue to support the security of the bitcoin network by continuing to mine. This is not a rational activity as they would essentially be paying money to secure the network (via paying more in electricity then the worth of bitcoin they mine).
Also the network is already more secure then it realistically needs to be right now based on the transaction volume
I'm not sure you read my earlier posts, I'm saying it's rational to continue mining so long as your operating costs are less than your income even if you never earn enough to pay for your hardware in the case where you have paid for your hardware from savings.
lets say I spend 10BTC (cash - no interest due) to buy a few miners. That is a sunk cost.
If I never get a return on that 10BTC by mining (ie. A bad investment) it is still possible to carry on if my operating costs are less than my income.
At the moment many miners have an operation cost around $130CAD per BTC, some won't earn enough to recoup the investment in hardware, but given the hardware is fully paid, quitting now when the price is $380CAD is premature. They are in the red but plowing on is better than throwing $250 away by stopping.