Well in that case, I suppose that everyone who takes out a loan and pays it back with interest is a scammer. I suppose hedge fund managers and pension funds are, too.
Cloud mining was once profitable to some extent (though buying your own hardware was always better). It is now a wraith, drifting along on borrowed money and shady schemes like Genesis Mining. Basically, there's nowhere to go with it.
Nice way to twist things to meet your agenda. A better fit would be someone starts a new business and says "Hey! So here's the deal. My business is going to guarantee $100 in the next week.
It's absolutely nothing like that. You're referring to Ponzi schemes.
While the vast majority of cloud mining sites are Ponzi schemes, the ones which are "legitimate" do not promise an exact amount of money. They promise that they will buy or produce mining hardware with your money, and then mine with it and give you some of the earnings.
This is a perfectly reasonable claim, because the cloud mining operators can still make profit. In the case of HashNest (run by BITMAIN), they produce a miner and mine with it, while taking maintenance costs and a few for their profit. It's fairly similar to any normal investment.
There is a difference between a bad investment decision (cloud mining) and a scam (Ponzi schemes).