I'm sorry but although the points you raise may be true that is not how they would appear to an infantryman, I know as I was one and for a little bit longer than 5 minutes.
Pride in ones regiment is a huge part of being an infantryman (I still have pride in the regiment I was part of that I left 12 years ago) and I don't know of many regiments that would be proud to take on a role which is often seen in the wider British Army and beyond as guarding 'guins for a living.
Yes (as I stated originally) there is a lot more to the RAF Regt than walking the fence line but the oft mentioned remarks about the 'short range desert group' will linger on as off hand comments about the RAF Regt always have and I don't believe many Lt Col's would happily let their battalion step into those shoes. Of course they'd no doubt gladly cherry pick the SFSG tasks which the RAF Regt are an important part of but the less glamorous tasks I'm sure wouldn't be as palatable.
Of course most of this is based on pure ignorance and misconception of the role of the RAF Regt, but in a British Army that in many quarters is still stuck firmly in West Germany facing off the 3rd Shock Army the thought of tootling around in WMiK's at Basrah doesn't have the same appeal as being an armoured infantry battalion racing across some as yet to come Salisbury Plain photostat battlefield.