Too many businesses insist on Ethernet for security reasons. WiFi still far slower then Gigabit Ethernet. MBA is fine because it is designed for size (not meant for significant projects), but on a Pro machine? EDIT: Forcing one to get (buy) a dongle to use a industry wide standard and expected connection on a business/pro level machine is bad practice. This is not about pushing advanced technology, its about supporting technology that is still top of line and ubiquitous. Dongles are also bad practice in industry, used only for very specific, limited reasons. They can get damaged, lost, stolen. Worse is damage to the Thunderbolt port itself. Remember why Apple went with MagSafe power connection?