Well Houston has a massive space industry too (hence why they call it "space city"). My thought has always been that he's been becoming more frustrated with CA for many years, but he just moved from SF to LA, and now he's moving From LA to Austin and Starbase, when (in my mind) it would make more sense to build and design the starlink satellites (among other things) in Houston where the space industry is much stronger.
You do bring up a good point about JPL being in LA, which would certainly have been why he originally started SpaceX there. That used to be the only focus of the company. I was thinking more about starlink just because that's what the article focuses on (among a few other things)
Maybe it was competition in the 1980's with the soviets trailing, but with the fall of the USSR in 91' the competition was over. Through the 90's and 2000's NASA and the DoD kept pushing new exploratory technology and increasingly advanced and technical engine designs.
SpaceX was notorious for eschewing experienced rocket scientists and grinding out work from novice engineers, but I think it is fair to say they still benefited from the pool of experience they did tap into.
I'm afraid you underestimate Moscow space cluster. In '90s, even in '00s their rocket engines - not quite from Moscow, a few kilometers away, from Khimki - remained world class. Realized project from, among others, Korolyov, less than an hour of drive from Moscow - Sea Launch, not realized but seriously pushed - Kliper. In 80's they might be unquestioned champions, not trailing - but I don't know your criteria, it's just what I see. Moscow had Proton-making factory, two significant space-relevant universities - MAI and MGTU, and several strong technical universities also related to space industry - MGU, MFTI, MEI... And there are others. So, in terms of being "the rocket design capital of the world", if you consider "rocket" to mean "space projects", Moscow with immediate neighboring region - not Soviets - was until recently (2008?.. later?..) pretty competitive. What LA region has of similar effects?
You do bring up a good point about JPL being in LA, which would certainly have been why he originally started SpaceX there. That used to be the only focus of the company. I was thinking more about starlink just because that's what the article focuses on (among a few other things)