The whole story thus boils down to a nice, illustrative all-other-things-equal experiment of how off-the-grid self sufficiency stacks up against a renewable energy power grid "done right". The latter winning by a large margin.
That being said, there are plenty of sunny places on Earth where the power grid is dysfunctional, or is hard to access. Those would be more obvious places for DIY solar panels.
To me, a lot of "off the grid" attempts look like elective attempts at re-solving issues dealt with by plain rural poverty out of necessity, often overspending on capital goods to do so (eg how much are storage batteries, shipped to Hawaii?). But even so, they are valuable as a different starting culture means different assumptions about what amenities are necessary, and different approaches to solving/suffering problems - eg the expectation that there will be dependable electricity for solid refrigeration, copious light at night, computers, and electronic entertainment - rather than simply shrugging off that the benefits aren't needed.