That's a utility argument. The counter might be: As society goes increasingly solar, the utility is required to produce less power, which cuts down on their operating costs (they're buying and burning something to move those turbines!). Encouraging more solar with low or no fees, or renewables in general, lowers the stress on utility plant, and in the long run is an investment itself. The solar owners are actually bearing more of the cost of future operations and maintenance, instead of the utility.