Why doesnt Android come with a File Manager?

It's something that just occurred to me, what's the point of having the functionality of mass storage and mountable storage if there is no first party way of accessing? I know there's third party alternatives, but the options that we have now like Astro and ES (which are old timers) are butt ugly and a frustration to use, as in a use-once-then-get-out-asap-kind-of-app. Is it to hide the commodity of folders installed onto the root of the storage by developers who refuse to keep it in the /data folder, or protect common consumers from accessing or modifying certain folders like the /Android and /data folder? What do you think, and if Google made one, what features would you expect?