I'd say due to the lack of focus and the resistance to recognise the importance of the aircraft in the British armed forces. Being a force still firmly believing in horse as the main source of recon let alone the thought of air attack. I'd say with hindsight they would have snapped him up. Have a read of the book called "no empty chairs" illustrates pretty well the thoughts on aircraft use in the British war machine before and during the start of WWI.