I think it's already the case that not being on the grid is financially best in areas with very low population and reliable sunshine, like parts of the Australian outback.
Also, cities (and all people everywhere) need to dramatically reduce power consumption no matter what the source is.
Industrial use changes things. Take the grid away and there'll be some unpleasant knock-on effects to prices for everything.
Large industrial users are already smoothing the grid, either with cheaper pricing for off peak use, and deals for intermittently taking surge from the grid. With no grid and no daily varying residential and office loads how do you smelt your aluminium or cook your canned foods other than at normal price? Does every plant need to be local to power generation now?
Having lived for 2-years on a school bus with an off-grid solar system, I don't see the advantage of investment in the grid.
I question whether, in 2018 and beyond, the advantages of the grid (sending power where there is none, borrowing power from where there is some) are better than very small batches of battery storage.