....

They're not talking about shipping water to Earth.

They're saying rather than spend money sending equipment to the moon to gather water, we need to worry about the water availability on Earth.

Even the paragraph before you quoted shows that person knows it would be for fuel

Deudney said he was struck by NASA's moonbase enterprise, the notion of extracting water from shaded craters for rocket fuels. Indeed, that vision is on the shady side without independent experts looking at the feasible cost and consequences of such an enterprise.

There is at least one person who doesn't know what they're talking about, it's just you