"Clearly you overlooked the point that a lot of USB 3.0 chip-sets don't work with many of the arduinos"
USB-C isn't only about usb3.0. If you look at USB-C pinout, you would know that there is usb2.0 data + and - and regular usb 5V and GND.
This is all about the connector. My phone uses type C, my earphones uses type C. I dont have good quality microUSB cable anymore(i have Leonardo, UNO with this fckin type B would be even worse to find). Everyone is adopting type C so why arduino doesn't do that?