Earlier quoted context omitted.
Isolation and centralization is useful for the corporation; they have more control over physical security, can manage it so employees tend to interact only with other employees, and it costs a lot less to have space for 12,000 employees off the interstate than to have them downtown (if Silicon Valley towns even have "downtowns;" I know far-flung Miami exurbs usually don't.)
Palo Alto and Mountain View have real places; the rest is pretty much all miserable sprawl. I miss working in downtown Palo Alto.
Likewise Sunnyvale and Santa Clara are quite anemic, but Los Gatos, Saratoga and even Los Altos aren't bad. MV and PA are great places to dine.
Cupertino is the only town I've worked in that never had a downtown.