Earlier quoted context omitted.
Emacs has many frustrating behaviors out of the box. Typo-> C-z->Crap->Grab Mouse->Expand Emacs Window->Scold self for not calling it a frame. "Frames v. Windows" thing aside, every behavior in Emacs is configurable. It's just that the default assumes that the user fired up Dired to seriously use Dired. The default assumes that the user is using Emacs as Dired and so it becomes Dired with lots of dedicated resources.…
BTW, you can run "killall -CONT emacs" instead of having to use a mouse and expand the window (which is hack anyway). You could also use cua-mode, which makes Ctrl-Z work like in other applications. Or you could use an "Emacs starter kit" which includes it (I started with "Emacs Prelude", although that doesn't include cua-mode if that's what you're after). Other answers are given here, including a one-liner to disabl…
Emacs takes a long time to learn and I think that's a good thing. The fact I grab the mouse after hitting C-z shows that I don't know the OS's underlying hotkeys for managing windows. It shows that I've been trained to use the mouse rather than actually control my computer. I love that Emacs points this out to me regularly.
Speaking of SuperUser, did you know that there's an Emacs site in beta on StackExchange?