No, you are wrong. If BTC fell from $100 to $50, buying BTC still would have been the better investment.
You would buy a BJ for 60 coins, and earn back, lets say, 10 coins. You spent ~$5750 and ended up with $500.
If you had bought BTC, you'd have 60 BTC, and at the end it would be worth $3000. Still the better investment.
Yup. Unless you get into touchy feelies soft valuations of your contribution to the Bitcoin network security (which you probably shouldn't unless you're running and mining on your own node), there is no scenario where a miner which produces less in Bitcoin than you could have had instead is to your advantage.