The idea that we have degraded the native habitat for gophers and thats why they eat crops sounds innacurate to me. My property is surrounded by thousands of acres of pristine wilderness preseve on one side and a developed town on the other side. Hiking through the wilderness area theres very little gopher activity. You see the mounds but its just not very much. Then you go into town and theres hundreds of them in the park thats being irrigated and in yards and everywhere. Even my own lot, half of it is untouched and the other half I grow things on. Of course they are attracted to the side full of tender green tasties being irrigated.
This in itself is why I almost think theres potential in trying to revegetate highly disturbed and degraded areas. My next door neighbor has about 12 acres of untouched native grassland and I see practically no gopher activity at all. At the top part of my property I have native grassland and have little to no gopher activity there as well. Yet, in my heavily degraded, terraced and grazed land (for the past 20 or 30 years) I have gopher activity almost everywhere! I hadn't even started irrigating or planting until about a month ago! My thoughts are that we are seeing so much disturbance from the gophers because there in fact is nothing down deep, all the roots are really shallow and poor forage for them.
Honestly though, I have only been there for a year and only have gotten roots in the ground in a big way about a month or so ago. I mean, after reading your post I am pretty much ready to start trapping them, haha. I just dont think that we really know enough to say that it has to be one way or the other. Considering our instinct is often to kill the pest, there has to be other ways that are more symbiotic.