ROI is just one model of thinking about mining. It is not the only one that make sense. An auto mechanic, plumber, electrician, or any skilled worker needs tools to accomplish their jobs and earn income. They have to purchase their tools upfront. While they can and do write the tools off for tax purposes, their goal is not to have a return on investment on their tools, their goal is too earn an income. They do not usually look at their paycheck and say, I haven't made any money yet because i have not made enough money that covers the cost of their tools (unless they borrowed the money but that is another issue).

Mining equipment is a tool to earn money. And unless you are amortizing the cost of mining equipment over time then you are wasting time thinking in terms of ROI. The value of equipment usually goes down over time. None of the calculators seem to be accounting for that. They keep the cost of equipment the same over whatever time period you are looking at for ROI. That is ridiculous and makes no accounting sense at all. And another thing is that the value of your mining equipment can actually either stay stable or increase based on the demand for equipment that is directly linked to the price of BTC (if it goes up, you mining equipment becomes more valuable because of its ability to always earn BTC no matter the price).

This doesn't mean you ignore the cost of mining equipment or do not factor it in to your finances. But the equipment is analogous to buying a car in addition to the tools analogy above. I get a certain value from using a car that is not directly related or impacted by the cost of the car. A car is a big money hole. It decreases in value over time and I have to keep putting money into it to keep in running in order to get the non-monetary value I get from its use.

I mine to make an income period and the rigs are the tools that allow me to do that. I do not consider recovering the cost of my tools as primary.