Sticking my unwise head into the lion's den, could it be that Mr. Everitt has been advised by the same people who refused to raise the base of some 2500 ft LTMA near North Weald some years ago, on the grounds that simultaneous SID's from Gatwick and various other movements, followed by one or more radio failure(s), would result in airliners at 6000, 5000, 4000 and 3000 feet at the same place, hence making it safe by everyone following procedures - at the expense of denying us some badly needed open FiR (as it was then - Class G now)?
At least the advisers would be consistent if this is how it came about.