On the rare occasions that I encounter non-Vim vi clones, I quickly run into missing features like these:

- deleting past the insertion point in insert mode

- visual mode

- split screen

- multiple buffers

- text objects

- macros

So even for people who don't care about Vim's syntax highlighting or autocomplete features, I'd assume real vi is a non-starter. I'd choose it over nano (no offence), but still.