This has been going on for a long time. Grandpa Duck moved into the Arkansas valley West of LaJunta in the 1920s. Otero County. Worked a job, saved and bought a farm there. The area was on the fringe of the 1930s dust bowl, and anyone who dryland farmed was screwed. My grandfather had water rights and did ok. In the 1940s and 50s, the region was a garden spot - some even dryland farmed alfalfa - such was the rainfall. My grandfather bought up people's water rights whenever they'd sell them then, and ultimately formed a small rural water district using some of them. As he aged and ceased farming he looked to sell the water rights, and none of the farmers were interested. All they knew were the relatively wet years of the 40s through 60s. So Gpa sold his rights to the City of Aurora in the early 70s - made bank and funded his retirement with the proceeds. And the first thing the City of Aurora did? Excavated and cut the well casing pipes off 10 feet below grade, filled them with grout, capped them and reburied them.
Last time I drove through the Arkansas valley on US-50 was in May of 2022, 100 years after my grandparents moved there. They wouldn't have recognized it: Dryer than a popcorn fart, and virtually no row crops. The house he built was dilapidated too. Solidly built, but last two owners didn't have resources to maintain it. I won't drive past it any more.
Your grandpa was a visionary.
I think he just wanted to make sure his ass was completely covered, so he could irrigate his crops if needed. The rest was just good business and having a commodity that was in high demand. The family that bought his farm didn't want the rights governing the associated irrigation wells at the time, but when I spoke with them 30 years ago they admitted it was one of the worst mistakes they'd made. Dryland farming in southeastern Colorado has been pretty hard since the late 1980s.