The trouble with this logic is that public utility commissions across the country have measured the impact that solar has on the grid, and found that not only does it not impose a cost, but it confers a benefit, in some studies up to 33 cents per kilowatt hour.
I completely agree with your core point, which is that there need to be costs associated with impact on the grid, to make sure that there's no incentivization of freeloading in either direction. Whether utilities owe solar owners a one time payment, an ongoing payment, or should be contributing to the financing of new construction of solar panels is an open question imo.
