Traditional Vi? I thought I was hardcore. Certainly an outlier, in a good way :)
Also very useful if you do a lot of context switching or are an occasional user, to make sure your brain and fingers are in "vim mode" (at least one other line in the file makes this rather obvious)
And once it's there, why bother removing it? I think you are in minority if you actively prune your vimrc for dead config...
I just tend to turn off things I only ever hit by accent (see also the :h override).
(my main reason for preferring original ex-vi is that when I typo a command, it beeps at me, whereas in vim the typo is usually some completely unrelated but valid command sequence and then WTF JUST HAPPENED and argh)