Cupertino did have a downtown along Stevens Creek and De Anza, but the area changed significantly in the 1950s and 60s when streets were widened and DeAnza College was built. Cupertino certainly doesn't have much of a downtown now.
Sunnyvale didn't really until they started building a clone of Santana Row that went belly up with the housing crash. Well I guess Historic Murphy Avenue sort of counted.
As a former Apple employee I cannot disagree more. Everyone at the mothership needs more sunlight, not less.
I can't even remember how many days I got to work when the sun was coming up and left as it was setting, or after it set. It was like a perpetual winter.
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.