This article is from October 31, 2009.

Apple.

An awful lot of it is explained by the lack of the need for minicomputers as consumer hardware began to make them unneeded and the downfall of DEC. While DEC tried to get into other fields such as workstations with their Alpha RISC processor, workstations weren't a great market either as they too were becoming threatened by consumer hardware.

I don't agree with the author stating that people expected that if one region would dominate tech it would be Route 128 and not Silicon Valley. Further, Harvard and MIT are part of Route 128; Yale and Brown are not, and certainly not Bell Labs.

I do agree that the Bay area in the 1970s and 1980s was first among equals, as opposed to the dominant/preeminent role it has had since then. Consider personal computers. Tandy? Fort Worth. Commodore? Suburban Philadelphia. The PC was developed at IBM Boca Raton (Miami) and run from there and Armonk/Yorktown (Westchester County), with the San Jose office having little input. Compaq? Houston.

Or software. Everyone knows about Microsoft and Seattle, but Ashton-Tate was in Los Angeles and Lotus in Cambridge.

There's a reason why the Computer Bowl during the 1980s had "East Coast" and "West Coast" teams, with Bill Gates captaining the latter despite Microsoft not having a regional office until it bought Forethought in 1987 for PowerPoint. (I suppose today the teams would be "Peninsula", "Valley", "San Francisco", and "rest of world".)

Does California’s constitution banning non competes and protecting people’s work they do outside of the office have anything to do with it?

IIRC Levy’s Hackers covers this.