This isn't a very well informed rant. Sandboxing exists so that malware doesn't get access to all of your files. The address book used to not be protected and look at the crapstorm that caused when Path accessed the address book without informing users.

And a file tree is a poor abstraction for "mere mortals". John Siracusa has a much better discussion of why an exposed file system is a bad idea in the last episode of the Accidental Tech podcast. http://atp.fm/episodes/6-live-like-other-people