I could say that if a coal producer wants to dump sulphur, radiation, C02 etc. into the air then it's "fair" that they recompense the people who live in the countries they pollute and the people they help to kill. Why should those who don't do this (people who generate their own electricity or pay to have non-coal energy) have to shoulder these costs?

Simple argument right? But no, it's a decades long political fight with no end in sight, because some groups have dispersed interests, while other groups have very direct incentives.

The same is true here, lots more rooftop solar would be of small benefit to most people. But it directly threatens some concentrated interests. And they will happily tell you that solar will destroy the grid, or net-metering isn't fair etc. etc. Not because it's true, but because it's in their narrow and short term interests to lie.