What will you do when it has been raining/cloudy for weeks straight like it has recently in California? For this period, wind has dramatically outproduced solar [1]. Even in the summer/fall, when there was severe wildfire smoke in the area, my solar+battery barely produced anything.
Sure, you can set up a propane generator (very expensive at the size needed for a full house backup), but then you are dependent on the propane-distribution grid. The dirty secret of "no-sacrifice off-grid" lifestyles is how much they are dependent on propane for heating and electricity.
Also, the grid's up-time is going to be better than your home battery setup up-time both because it is constantly maintained and it has access to a greater diversity of energy sources (wind, nuclear, fossil, large-scale storage) that are firmer than anything you can attach to your house.
The fact is that modern living standards (cars, TVs, comfortable temperatures) require a much larger amount of energy and energy-availability than most people can produce on their properties with solar. The additional energy has to be imported somehow, either from the electric grid or as liquid or gaseous fuels.
1. See Renewables Trend at http://www.caiso.com/TodaysOutlook/Pages/supply.html
This is exactly my sentiment and is the reason that we have made ourselves independent from the grid.[1]
However the math gets very difficult if you need to charge an electric car ... it's a tremendous amount of electricity to keep one, not to mention two, cars topped up after daily use.
The extra panel and battery requirements for cars are such that it really does make sense to be grid-tied and arrange your charging on off-peak hours, etc. That is what makes this so frustrating for typical homeowners - there's an obvious and sensible symbiosis here that would work well for (most people).
[1] That, and the fact that I hate PG&E with the burning fire of 1000 suns.