There is a good map on the wiki of Concentrated Solar [1] showing the Direct Normal Irradiation. The US West coast is in somewhat of a unique position (as is Australia, South Africa, and a couple of others I suppose): high density population centers in areas with a lot of solar radiation. In those areas it might very well be the best method available (dunno, could be). Transporting electricity at distance is non-trivial however. Plans to put these installations in the Sahara and transport it to Europe via high-voltage DC lines have pretty much gone nowhere (https://en.wikipedia.org/wiki/Desertec). So non-competitive was more a reference to the constraints that it imposes, but I could've been clearer for sure.

[1]: https://upload.wikimedia.org/wikipedia/commons/c/c7/Global_M...