There's a big difference between thunderbolt and thunderbolt 3/usb c. The former was proprietary by Apple/Intel, and very expensive, so no one else added it to their machines, and onlu very high end accessories included it. Usb C is the new standard that is already being adopted by most manufacturers, so I'm very confident it will spread quite fast. Not saying that launching a professional laptop in 2016 with just 4 usb c ports was a good idea though, but I guess they're really pushing for the standard to be adopted as quick as possible.