Well yeh! but no but yeh! because they can!
Simples!
Why does the RAF use QFE? For the same reason mutts lick their nuts - because they can!
exactly.
I think the RAF are in the dark ages regarding QFE
QFE is better for military pilots flying MIL aircrafts, as they have advanced equipment onboard and using only RAD ALT and are not using cheap pressure altimeters. again, just that simple.
Military stuff are always a step ahead, may it be aircrafts, software (they have military grade programming languages and MIL software standards), and onboard avionics equipments.
If all of us can just upgrade our pressure altimeters into rad alt then we can scrap this QNH thing altogether.