I might be inclined to agree, but doesn't the wild success of so many California companies where even these non-competes are unenforceable suggest the net value isn't high, maybe even negative?

Massachusetts has had one modern era wildly successful civilian high tech period, stretching from the minicomputer era to the early PC era (both Visicalc and Lotus 1-2-3 were done in the Boston area). But this part of its high tech scene died hard by 1990 (and I left the area, I was an eyewitness starting in 1979); non-competes were I believe part of the problem with Silicon Valley wildly out-competing the Boston area.

Since then I've heard things got better in the web era, but still nothing compared to the Bay Area.