Because they have no idea of what they are doing. At best they are copying others but most likely they are afraid you will not be working without someone looking over your shoulder. A lot of times they do it as staging theater for investors (look at my team working in a cool hub) others to impressive customers (having an address in a locale is part of branding). No one does it for better ideas. Cheaper to fly everyone for a retreat if that was the case.
Its amazing how banks are offering reduced interest rates and more money if you are willing to rent out a building at a loss. If it's happening here, it's happening everywhere.