I can appreciate making formerly arable lands arable again, but beyond that, no.
What's the time limit on when they were previously arable? 50 years, 100 years, a thousand years, Ten Thousand Years?
I agree its wrong to take freshwater from an aquifer for irrigation. But they're talking about taking salt water from the ocean, taking the salt of it and using it for irrigation. If they're using solar energy for the desalination, that's a great thing.
I agree about lawns. The only reason I can see to have a lawn is if you have children that like to run and play on it. Grass is the only thing resilient enough to put up with that kind of abuse. There are grasses that don't need watering, so they turn brown during the hottest part of summer, which is perfectly natural.
On the old prairies the grasses dried up during the summer, or even burned, and the bison trampled on them, and that's what the grasses were used to and adapted to.