It's not like Vim is perfect, and even taken the sharp learning curve apart, there are many things that are not ideal. But so are other tools. I tried some IDE here and there, but never found an improvement in my productivity – which would be certainly easier to improve by not going to sites like Hackernews. :D
I do find some things in some IDE horrifying, like having the amount of RAM consumed by the application displayed in the default interface, and seeing it growing while you don't ask anything to the application. I mean, even dropping the fact that it does require so much resource to do nothing, what a strange idea to clutter the interface with this data if the goal is to let users focus on there issues.
But that's no reason to be zealot of any other editor, including Vim. I'm rather confident that going with a matrix with measurable metrics, Vim wouldn't have rated 100% everywhere nor any other tool would.
To me the greatest feature of vim is that it's available virtually everywhere, so you can take it and the skill you gained on it everywhere. It doesn't make it something should use all the time, but it makes the point on how it might worth the effort to start learning it. That also a positive retro-active loop, that explain "why Vim is so popular", I guess.