That looks to be a population map:

https://xkcd.com/1138/

Which is what you would expect of a stat of "number of outages per state". If it's not normalized for land area, population, and all the other primary contributors to the total number of outages it's a useless stat. San Francisco has more people in it that the entire state of Wyoming.

Texas' power is also cheap, so to justify batteries they would have to not raise the cost of electricity that much.

The current cost of grid batteries is hidden, but it's not too hard to find out, and it is indeed quite cheap. But if there's no mechanism to get paid, ie ability to do time arbitrage in the energy market, then they do not get deployed.

Electricity market design and the ability of ISOs/PUCs/utilities to adapt to changing technology are bigger barriers to batteries than their price.