Yours is the important point. Germany could only win the Battle of Britain by adequately protecting the various bombers they had on hand. A high speed interceptor might have a lot of value to the RAF, but only very limited value to the Luftwaffe while flying over England.
The Luftwaffe's mission was not to shoot down RAF craft. Its mission was to cripple the RAF AND maintain a bomber force that could smash the Royal Navy. Shooting down every single British plane matters little if the German bomber force crumbles.
Please mod parent up. (It is a rant, but it is a rant that hits the nail on the head.)
Curves are a means for teachers to avoid explaining to anyone what is required to earn a particular grade. So they hide behind their aura of authority and cook up a post hoc rationalization.