California, a sea of Macs, all people switching from laptops running Linux

When I studied CS 15-11 years ago in France, nobody had laptops in class. All practical work was done in a computer lab. I still find it weird to see a picture of a lecture hall and a sea of computers. What do people do with them?

This aside, in the dorm Macs were maybe 10-20% with a healthy amount of mac hating.