Quantenna Announces World’s First 802.11ac 10G Wave 3 Wi-Fi Product LineCurrently 10Gbe is just too expensive to implement so they cant go for that but using a fast CPU and the PCIe busses is a much better way for internal design than RGMII and cheaper than 10Gbe interface implementations.
http://www.quantenna.com/pressrelease-09_08_15.html
World’s Fastest 10Gbps Family for Wi-Fi Access Points Features True 8x8
and MIMO for 5GHz and 2.4GHz to Manage High-Density Wireless Networks