From your link:

"...solar customers avoid paying many of the fixed costs of the grid that are factored into their monthly bills. As such, these fixed costs are then shifted onto non-solar customers."

The same could be said of folks that switch from incandescent to LED light bulbs (approx. 80% reduction in energy use). Or customers that lock the door and go to Florida for the winter....they are not paying their share of the fixed costs either and are shifting fixed costs to those who did not change light bulbs nor go south for the winter.

This is exactly what I said above: fixed costs ("facility" costs) need to be separated on utility bills from the variable kwhr costs. Facility charges must not be "factored into" the energy charge.  Some utilities such as our local REC now do this with their approx. $40 minimum/facility charge per meter per month. Others will have to do this. Energy charges will go down and fixed facilities charges must go up when the two charges are separated and accurately billed.  It will not be easy but needs to be done to be fair and accurate.

Utility company billing problems are not solar, nor LED, nor vacation, nor insulation problems.

Fixed costs are fixed costs, they are not variable (energy) costs.