Something I run into often enough, so it deserves to be blogged.
I use the "Hide Application" OS X command a lot. I rarely ever minimize a window. I prefer to hide the whole app. I try to keep my laptop screen pretty focused, since it's a smaller space to work. So I often use the "Hide" shortcut key (⌘H), to hide the current application and will repeat that a few times to clear the deck.
But OS X won't allow me to hide all of my apps. No, one has to remain unhidden. Even though you can't truly hide the OS X Finder app entirely (the desktop and any icons on it remains on-screen). But hey, I'd even be fine with hiding everything but the wallpaper and Dock.
The annoyance from this "one app must remain" rule is that if you hide the last unhidden app, it either: won't let you (new as of Mavericks), or will unhide the last hidden app (prior to Mavericks). This is never a welcome behavior. Never.
And, if you hide the last app on a given desktop with any full-screen apps running, it will pan over to an adjacent full-screen app (one of the 200 new features in Mavericks, I think). Why?
I guess what I should be doing is selecting the app I really want to use and use the "Hide Others" command, which will hide everything but that app. Yeah, okay, I can. But still, this seems like a silly, arbitrary rule to me.