There's really no mystery here. The reasons are the same as in every other part of society where outdated conventions are maintained despite massive, obvious problems. The phenomenon itself is as predictable as the arguments used by its defenders, mostly variations of "it works for me".
I think there's more reasons that are not so negative.
First of all, vi predates all those others. That means it's always had an active userbase werken other tools were in fashion. Changing the bindings at any point in time would have hurt a lot of people's muscle memory. It would also be extremely annoying when one has older versions on some machines with the old bindings and some with the new. I deal with the Mac vs Windows/Linux copy paste problem every day.
Also, vim just has a ton of functions and there's always going to be some shortcuts that will be awkward on some or other keyboard layout.
Finally, you don't have to use it :) or you could distribute your custom config file with bindings to every machine you use.
… or also because it’s significantly more productive than any other editor. But hey, it’s much easier for you to assume everyone making a choice for themselves is part of some cult than giving them the ability to think and make good choices.
I use heirloom vi (while making it clear when asked that I doubt the person asking me should do the same ;)
I was basically forced into learning vi to begin with (editing things on a -very- heterogenous collection of servers) but then found after a few weeks that I found it surprisingly pleasant and stuck with it.
Then again I don't recall sending a vi instance anything involving the control key except for Ctrl-C, Ctrl-L and Ctrl-Z.
It’s not problems, it’s opportunities you’re missing, because you don’t understand and aggressively don’t want to understand the actual reasons why people are using it, whining about elitism and other bullshit instead.
Inertia, traditionalism, elitism, insider culture, ignorance, "good enough" mentality, blind spots, cargo culting, ...
There's really no mystery here. The reasons are the same as in every other part of society where outdated conventions are maintained despite massive, obvious problems. The phenomenon itself is as predictable as the arguments used by its defenders, mostly variations of "it works for me".