That's the current incentive structure for better or worse.
Someone (maybe the USDA, maybe SV) needs to pony up money to compete with using that ground for cropland. In an ideal scenario, the ground surrounding waterways should be easily worth $300/acre (which enables it to compete with row crop rental prices).
Problem is people laugh at that concept and then complain we have overproduction, dwindling soil health, and poor water quality.