The thing is, though, the subset of vi you have to learn to is relatively small. You need to know how to enter and leave insert mode, how to delete, and how to quit with and without saving. (For a non-vi user, the difference between knowing and not knowing those simple things is significant)

This is generally enough to edit the few configuration files you may need to touch before you install emacs (network, sources.list, sudoers, etc).

So even though the use case is small and shrinking, the amount of "vi skill" you need is pretty low as well. There's really no good excuse to avoid it.