On the particulars of residential solar deployment, it's the utilities. (And to a degree, the US's completely backwards permitting system which varies by municipality and mostly exists to drive up costs for everything and maintain stasis.)

Utility leadership is highly tech-averse, change averse, and rooting for the "clean beautiful coal" sports team. But also they can't imagine a future where there's massive electrification, with people switching from gas to getting their car energy from the grid, and being able to profit from it. It's somewhat shocking, but just like US car manufacturers, utility leadership is from a different era and are rentiers, rather than innovators.