And the problem with this is, the miner is taking all risk of the business considering hardware expenses as well as electricity.
Only before paying off the hardware, and assuming miners are keeping an eye on profitability to ensure they are covering their electric costs as well as making a profit.
Assuming most people start with a machine they already own, their only risk is recovering the initial electrical expenses. Once they have successfully mined their first coin and cashed out and paying off their electric bill, the risk becomes more and more minimal as their profits should act a buffer should a coin's value drop before they can cash out on future payments.
Also, many people here get free electricity, such as University students, etc. so the risk is even less, maybe if you want to count wear and tear on equipment, but still pretty minimal.