The "obvious" reason would be if a person is used to terminals but not vim, as ctrl-c usually kills processes.

I think a lot of confusion could be avoided if distributions like Ubuntu, that are commonly used by new Linux users, were to set e.g. EDITOR=nano in their default ~/.bashrc. That way, writing "git commit" from a terminal, typing "v" inside less, etc. would all bring up nano instead of vim by default.