Why is that the way it should be?
To the best of my knowledge France, Holland, Brazil, Germany, Argentina, Spain, Italy have never appointed a foreign manager, at least not in the modern era. Some of those nations have been as low as England are currently and fought back, Germany after euro 2000 for example so if those nations can find a way back with one of their own, England can aswell.
Each country should have a manager from its own countrty, otherwise why cant you pick foreign players from the premiership as well?? I wouldnt like to see a foreigner lifting the world cup tbh but thats just my opiniion