If you buy a miner, you pay for it x worth of BTC. even if it is payed in USD it is still worth x BTC at the moment of purchase!
If the miner mines less than x BTC alltogether than you lose because you could have bought x BTC instead of buying the miner.
This is a fact. It has nothing to do with assumptions, theories, feelings, subjective way of looking at the world. Just a very simple math.
The oil price has increased heavily in the last years. You can tell start telling me now that through investing in Bitcoin miners, I might have lost the profits in oil investments.
That is the same kind of argument.
Yeah. Of course, that is simple. However you would also be right if you said "If you had invested in Apple stocks some years ago instead of... you would have more USD than before, simple math." It is just as nonsensical.