I agree that UK phraseology seems a bit potty and many foreign crews still ask "confirm cleared for the ILS?" to which I reply "affirm, cleared for the ILS" - then watch them closely! In the case of Heathrow a problem arose many years ago when somebody who had been "cleared for the ILS" went down to 1200 feet at 10 miles - God alone knows why. There's a lot going on under our final approaches so our procedures have to be fail-safe to prevent conflict with helicopters, clockwork-mice, etc. Maybe we're lucky in having a dedicated final director frequency which rarely goes bananas so there's plenty of R/T time whereas an approach unit trying to pop traffic onto the ILS and dealing with other traffic might well have problems.