At the time of development of the G30, the connection capabilities of Bluetooth were the most stable and reliable available.
Wifi was still relatively new and did not satisfy the requirements of our technology at that time. You will find that our more recently launched equipment incorporates Wifi as this has since become a widely used, superior means of connectivity.
We have a Wifi bridge called the GCAST if you'd like to convert your controller to Wifi instead of Bluetooth. Check it out here.