I know this seems unfair, and I see this response a lot here in discussions. Reality is though that there is a large amount of Teslas in this area. The number of Tesla cars in California outnumbers any other state. While on a map it looks like there are big gaps in the Supercharger network, it is not about covering area, it is about providing Superchargers where there is demand. The demand in California and especially around Los Angeles is much higher. LA county also is close to 14 million people. Add in the surrounding counties and it's easily 25 million.
Tesla doesn't favor any region because they like them better, they build where there is a higher demand to serve their customers. I live in Los Angeles and I see a lot of other Tesals charging when I drive around California. At several California SCs I had to wait in line. There are always other cars charging. On my 4300 mile road trip all the way to Minnesota I charged at all the Superchargers on the way that connect the coast to coast line. I saw maybe 3 other Teslas on the entire trip that included 30 stops at Superchargers. The difference in how much demand there is couldn't be more obvious. Tesla is doing the right thing, they build where there is high demand.