Different cultures. At one point Pixar had most of the bathrooms in the main building. The idea was that people would run into each other and share ideas rather than get siloed in there specialties
On the other end of spectrum, Microsoft used to tout the fact that everyone got an office, with a DOOR! And I mean everyone. Even a lowly admin right out of school. They felt it let people concentrate and more importantly take ownership of their own space since they could decorate however they wanted. Also their snack rooms looked like a mini mart with no paying. Want 20 mars bars, go for it. Need 5 jolts for the afternoon, have at it. And then there are the classic video game rooms...
USED to be the fact is correct. We're all being merged into more open concept spaces, which I much rather prefer. They're definitely a different company now.