From my POV why would someone spend $200k for a property only to lease it out at $900 or $1000 a month rent(crossing fingers nothing breaks AND crossing fingers tenant doesn't stick you) vs spending $30k on mining hardware (which BTW is deductible along with the electricity) to make a steady $3k-4k a month mining? I chose the latter. My only regret is that I didn't spent $200k on mining.
There are for sure arguments for both sides. In a lot of industries a 6 or even 12 month ROI is fantastic. But there are risks in mining. If it was a steady 10% return on your initial investment in perpetuity then, duh, choose that. But you have to worry about hardware breaking, hardware becoming antiquated, mining of profitable coins being optimized, or even the coin(s) that you store your profits in tanking.
It's a very complicated equation.