Bret Viktor's oft-quoted "Inventing on Principle" talk touches on this subject where a lot of research has shown that bimodal editors are worse. While I can't argue for how true that statement is, it's certainly been my experience. I always find it jarring to think I'm in command mode but I'm actually in edit mode or vice versa. Any vim user has had the experience of pasting text in command mode. I just absolutely hate bimodal editors.
Additionally, staunch vim (and emacs) users I know seem to spend an inordinate amount of time screwing around with plugins to get some pale version of behaviour you get out the box on any halfway decent IDE or even text editor.
I feel the same way about learning yet another series of keyboard shortcuts for, say, tmux/screen.
You could argue the mouse is slower. I'm not sure if this actually holds up to empirical measurement (or at least not to the degree that's claimed) but the point is, the barrier for entry is so much lower. You can just click around and find things. If you find yourself doing something a lot, you can find out what the keyboard shortcut is.
Thus you don't need to spend 50 hours upfront on a GUI editor.