It's the 2,800 workers in its current headquarters (which is only a few blocks away from this site) plus all those housed in rented space around town. How do all those workers get around town now?
"Hang on while I log in to the James Webb telescope to search the known universe for who the fuck asked you." -- James Fell
Do they own the land where you would prefer they buiid? Is the owner of that property willing to take an even swap with the land they own at this site?
I mean, the entire town is only 10.9 square miles and has a resident population density of almost 5,200/sq.mile - I guessing there's not a lot of empty space that's just waiting for development.
"Hang on while I log in to the James Webb telescope to search the known universe for who the fuck asked you." -- James Fell
Cupertino isn't much more than industrial parks these days; part of that non-geological Silicon Valley, you her so much about. In California's economy, not much else, from malls to municipals, survives there.
'Residents' are nearly an endangered species; which is why they'd welcome another industrial earner in order to stay on the map.