This makes sense, but you may be leaving out two relevant (ASIC Mining gear) market segments:
1) New Bitcoin investors that prefer to mine their coins instead of buying them (there are different reasons for this that have been discussed somewhere else)
2) "Corporate Miners" that need to stay on top of the game
Also, you should be very cautious when declaring the whole mining industry "not profitable at current difficulty levels" - as long as Bitcoin prices keep moving they have, it will be extremely difficult to prove this assertion. Looking at ROI in BTC alone can be an extremely misleading simplification.
I somewhat agree with the above paragraph, but the following one seems just wrong: since you pay the device in BTC, you have to consider only the BTC itself: exchange rate with other currency is totally irrelevant, since you had anyway the option of "just keeping your BTC" and having them appreciate exactly the same.
I'm quite tired of having to explain this time and again, it's so obvious but people keep getting it wrong. Will they ever learn?
You are wrong. Your pretentious attitude sucks.
Can we just stop this pointless argument?
Any device paid for in BTC that won't return the original payment price in BTC is not worth purchasing. This is most devices on the market now, if not all. This is the "buy and hold" argument. (Not considering the aftermarket resale of hardware, also known as passing the potato to the next sucker.) Anything paid for in fiat should look to the ultimate return value in fiat, regardless of BTC market fluctuations. This also depends/relies on selling off the mined crypto to return said fiat. Saying "I hold 5BTC for a device I paid $5000 for" is somewhat meaningless because you've input $5000 and output nothing. If BTC crashes to $200 before you can cash out, you've spent $5000 to get back $1000. Or saying you took out a bank loan and got a crap ton of BTC at $1100, now you've got a crap-ton of bytes on speculative currency and cannot make loan payments because you lack fiat.
Why we're still arguing about this, especially outside the speculation thread, blows my mind. Believe in utopia where holding BTC while you are paying so much for mining hardware that you can't pay your rent/mortgage makes you some crypto uber-god if that suits you or be realistic and understand the dynamics between fiat and a speculative currency and how the ultimate need for fiat overpowers the "holding power" of a crypto, but stop trying to convince other people that one way is the true way.
We're all in this to profit, be it through life experience or dollars, now let's push this thread back towards relevant AM information and move the bickering elsewhere. I'd like to be able to check this thread every couple of days, as a shareholder, to find relevant information on AM. Not return to the same bullshit bickering about share prices vs. dividends vs. speculative portions of the network.