With the classic OS, all the windows were supposed to work this way. And it seems most apps still do remember their window positions, making it easy to find them. (Expose even keeps the positions consistent when you 'zoom-out'.) Which is why Mac users tend to position their windows rather than relying on alt-tab or the dock or another app-switcher.

(IMO the spacial Finder was designed around floppies and small folders and didn't work so well with hierarchical folder views, so no big loss...)