I still think you're just trying to hire yourself and its kinda gross. Its like being British and refusing to hire someone that doesn't read or know about theregister.co.uk. Sure, most people probably should but there might be a great dev out there who don't and its extremely cruel to "other" them.
Does vim always happily tell you that its running? It used to be the default diff tool on devices I worked with and IIRC it was just a blank shell in some cases, so it might be non-trivial to work out if you're in it, without knowing it.
So yea, its probably interesting as a challenge but it doesn't prove shit, outside of "you like vim". I like Jetbrains products but I wouldn't assess someone's ability based on how someone might use the products, but rather what they create by using them.
