Solar homes not only use less 'product' (and therefore give the utility less money), but they also put power back on the grid at times when the utility generally doesn't want/need it, and onto a grid that has to be managed according to complex capacity and demand balancing.

Bottom line is not only does the solar home reduce revenues, but the homeowner gets money for giving the utility energy they don't want when they don't need it by using the utility's transmission system. Not exactly a sustainable arrangement.

Here's an interesting read against it, from UC Berkeley of all places: https://energyathaas.wordpress.com/2016/01/04/billing-tweaks-dont-make-net-metering-good-policy/