So you don't think apple can break up the app into various components and provide a single installer and call the whole bundle "iTunes".

And failing that, you don't think users are capable of installing multiple things or coping with a re-brand.

But if they did this only on the Mac all these things would work. Windows is the key.

Sorry, I do not think this is the reason. More likely they just don't want to put resources into a ground up overhaul of iTunes.