A coal power plant does not get paid retail rates for the power it generates. The utility company charges more precisely to pay for transmission and the people to maintain it.
Let's punish the free riders and reward the people who are reducing the total societial cost of energy.
The fact that solar owners get access to the energy grid for free seems like a clever way to punish the free riders by increasing their costs in a roundabout way.
Don't want to pay the higher costs for your power grid? Then upgrade to cleaner energy! Sounds great.
The companies that operate grids are not the free riders. By having idiotic legislation that allows solar owners to free ride the grid, you only punished the utility company. Sometimes they own power plants, sometimes they don't.