The usage is a big cost for any utility provider, but another huge part is keeping everything maintained and connected across the entire grid. That costs man hours, materials, you name it.
If you swap to solar and pay 0$ per month, yet you still incur costs to your utility to keep lines running to your home and your county, then a flat monthly fee to charge for that unused connection to cover your capacity to use it when needed makes sense.
Something had to give, idk if the path they’ve chosen is the right path however
How so? Did you not invest in solar in order to decrease your carbon footprint?
If you did it to save money, the evidence is pretty clear that without subsidies a lot of green industries are unsustainable. Government policy can change on a whim.
Selling solar as a means to lower your costs in an environmentally friendly way, then raising prices in a way that cancels out those savings and smugly telling angry people that they were supposed to do it for the environment without concern for cost to themselves is only going to make them less receptive to your cause.