The point is that water didn't just become scarce all by itself. It was the result of the economic activity upstream. To be honest I don't know what those people can do now, after the ecosystem collapse. But the situation could have been avoided in the first place I suppose. "economic" and "ecological" thinking need to work together to begin with imho.
Or maybe "economic" vs "ecological" is the wrong dichotomy and misleading terminology. Maybe ecology should be just part of the economy. Who knows.
I think the labels need some work - this is not a fight between economics and ecological science. It's just that economists view a system as a robust, constantly-adapting set of tensions between different market forces, while ecologists look at systems as a fragile set of fixed energy flows.
I think it's interesting that the Aral Sea is an environmental disaster. This reflects a mindset that values stability, and sees any change as bad. You could equally view this as an environmental triumph - millions of hectares of previously barren land is now flourishing, providing not only a huge crop yield, but also all that goes with that; animal life relying on the now-abundant food and water, humans tending and improving the landscape, etc.
Or maybe "economic" vs "ecological" is the wrong dichotomy and misleading terminology. Maybe ecology should be just part of the economy. Who knows.