This comment needs more attention. 47 people have suggested this be done, and it already is, in fact, being done

This $10 isn't nearly enough for actually maintaining it. For customers without net, it's not just $10. It's $10 plus some per-kWh cost to try and scale it based on your actual load on the grid equipment. If it was a flat rate for all customers it would have to be a good bit more than $10.

I think the idea is that this number would have to be much larger

There's a fixed cost and another cost that scales with usage. For instance, the California E-1 rate (non-time-of-use) is about 42 cents per kwh. Of that, 25 cents is transmission (long distance lines) and distribution (local lines), and 17 goes toward generation (if someone switches to another electricity provider, it's this 17 cents that would go to that other provider.

Scaling the cost of the grid with usage serves as a price signal for people to conserve power, as opposed to it being jumbled behind a more comprehensive tax or a larger flat fee.

That's probably the value of being connected to the grid in case you need power, but not the value being able to sell your excess energy back.