For one thing, because felines grow up associating kneading with the comfort of Mama Cat and her milk, the habit might be soothing.
If you're thinking of adding some felines to your office, take note from user kyonu who says that one to three office cats is about the maximum amount you should have.
Researchers studying the bones of the earliest domesticated cats in China have discovered the first felines to live with humans 5,000 years ago were instead relatives of the Asian leopard cat.