Even at Microsoft probably you cant find anybody that could explain.
Do not forget : the Microsoft goal is not to sell you an OS that is stable, clean
fast and efficient for a very lont time. The goal is to send you an OS that link
you as much as moppsible and require you to pay regularly
Why do you expect them to spend more time in clean programming and to do things
in order to enable you to run the same computer longer without buying a new computer
falt enought (with a new windows licence) ?