RAF is Royal Air Force, the name kinda gives it away Air = Airborne assets, since when did the Navy and The Army have the right to own airborne assets and now dictate that we should be binned and merged within them 2.
Its common knowledge now that Air Power is they key, once you gain that then you can send your ground and ship borne troops in. You need a well structured command and it takes many years of training for this to be of use. Soon as you change things especially a huge change like this then it will effectively reduce the capability of the airborne assets for years.
In this day and age with god knows how many airborne assets you will encounter , yes you can see reason we dont need the RAF, But if the likes of Iran,China North Korea and even Russia raise there fists believe me we will need the best air power we have, otherwise we will have to rely on Uncle Sam once again.