Why do you think that? Vim is perfectly fine for real world purposes - I use it for real world purposes all the time, as do a lot of other people.

Not only do the basic vi commands make my life easier (My mantra is if I have to press the same key more than three times, then I'm doing it wrong - you quickly learn to navigate by words, brackets, lines, search and judge how many of these away you want to move - eg instead of wwwww to move forward five words you can do 5w, to turn "abcde_" into "_abcdeabcdeabcde" you can do 5x3p - silly examples I know, but this makes it very fast an efficient to navigate and edit text), but with vims additional features and with a small handful of plugins there is nothing that a GUI IDE can do that vim can't.