Spacemacs solves the problem of discoverability by displaying all modal keybindings currently available, if you started typing a modal command sequence, but haven't completed a command yet. The additional bonus here is that once you internalise these commands, they stay the same while you execute them much faster. In mouse-centered environments, one would first learn how to do an action using a mouse and after he felt the need to be faster, he'd need to learn the key combo from scratch (for the sake of the argument, let's ignore the few common conventions like F1, cut/copy/paste and undo/redo).

On the other hand, I agree that starting out with CLI is a bit painful. IMO, the middle ground taken by Spacemacs really should be researched (and used) mode.