My 9 and 11 years olds write Python in VIM, and have been for about two years. Learning VIM itself can be fun, if you teach it properly. And it is a skill for life.
How do you teach kids that? I know kids learn fast, but still. Aren't they in a phase where they ought to catch on 'normal' things first in apps, isn't wrestling with vim averting they concentration from what they should be paying attention to (python)?
Quite the opposite. Instead of teaching them "use this arrow key" I'm teaching them "use this mode". And since they are paying mostly attention to the Python, the VIM skill that they are picking up along the way is hardly even noticed.
In a similar way to another respondent, I use vim because my first computer at university had it (well, Vi) and it's always there.
We started with a goal, in our case it was to recreate the car from the `gti` command (git wrapper). I created a file with maybe a dozen lines of 72 spaces, and let them get to work. They started with basic hjkl navigation and the i command, then they learned to replace with r and jump to specific location with /. After that I was simply answering their questions, as they already understood that everything has a shortcut.