It would be too much responsibility. The window uses the view, it never modifies it. Therefore, it manipulates a read-only reference to the view.
The view is supposed to be managed completely externally to the window. If you want it to be available somewhere in your code where the original instance is not known, it's your problem, SFML is not supposed to help you
But don't worry, things have changed in SFML 2, and this is not an "issue" anymore. Views are manipulated by copy so basically you don't need to store the view outside the window anymore.
