I expect utilities will be big Powerwall customers.
It might make a little more sense for some consumers due to the excessively high retail rates for electricity in some regions.
The more expensive the peaker, the faster the payback time.
In many places, the utilities aren't allowed to charge different rates over time (or if they do, it has to be in the form of a discount/incentive vs. the single-rate price, it can't be punitive) even though power costs more to produce at some times. Smoothing out demand by pushing storage out to the edges of the grid seems like it would be a benefit to them.