There’s certainly some reasonability to that. However, if the person decides to terminate service, maintaining the grid doesn’t become any cheaper for the power company. The lines are already installed, the connections made, and the company will continue to upkeep your connection all the way up to your home, even if it is terminated locally. They’ll do that just in case you or future homeowners no longer generate power and wish to continue service, and your neighbors will likely still be using it anyway. So by that same reasoning, maintaining a just-in-case service connection that you don’t typically need because you generate your own power also doesn’t result in increased maintenance costs to the power company. So there is also an argument to be made that that cost shouldn’t be pushed to them, but to the power drawers that the power company actually wants to serve anyway, the ones motivating them to build more grid in the first place.