Right, Macs always have had the premise of "spacial window management" (or that's what Siracusa called it), so that's probably how you are 'supposed to' do it.

Full Screen Mode was their answer to maximize, going back many years now (10.7).

The spatial Finder was something different: having each folder open a new window, and that particular folder's window always re-opening in the same position on screen, with the same window size and same layout of files inside. Having the position of each folder remain consistent and persistent allows you to remember a file's spatial location much as you would for a printed document on a physical desk (exactly where you left it), rather than having to recall its path in the file system hierarchy.

Obviously all of that works better if Finder windows don't usually fill the screen, but it's not a hard requirement.