Profitability calculators typically rely on the current market rate of BTC. Even if they paid for electricity, they could make up for it by keeping their earnings in BTC/whatever. Whether that's a smart decision is another issue, but for some mining is like a startup in that you burn cash early in hopes of a big exit down the road.
Edit: Several people have pointed out that you can just buy BTC or crypto directly. Besides the initial hardware cost (which requires cash up front) how do you generate income to buy crypto on a regular basis?
Edit: Several people have pointed out that you can just buy BTC or crypto directly. Besides the initial hardware cost (which requires cash up front) how do you generate income to buy crypto on a regular basis?