To get annoyingly serious on a funny post, the one huge danger of GUIs that I've personally witnessed in many of my juniors is that they abstract away the need to understand the tool you're using.

I regularly use a Git GUI, and I might have to google the rebase command for more complex tasks, but I know how Git works. I know what I can do with rebase, even if I don't exactly know how to. If you only live in the GUI, you can get far never understanding the system. Until one day, when you fuck up a commit or a push, and you're totally hosed because there isn't a pretty button with the exact feature you want in your GUI.