I have wondered how much of this is also due to markets. A lot of governments and security-centric nonprofits (eg hosptials) use PHP instead of Rails, which seems much more popular in startup land. It could even be that PHP is used fairly evenly across the whole US, while Rails is used more on the coasts.

Disclaimer: I don’t have hard facts or even anecdotes, I am a functional-first developer who marvels at any language which actually has jobs on the market :)