Make me wonder why they didn't use the VP system for haunts.This is definitely my experience. A couple of times everyone failed the RK check and then it was pretty much no fun. If this was a Call of Cthulhu or similar game, then such failure is expected and the answer is "to the library to do some research!" and I think once that's actually what we did -- we left and asked for help. But D&D is often structured so this is impossible, and when this last happened to our group we just made random rolls and looked sadly at the GM until they took pity on us and said "having tried a variety of things, you have landed enough to make another RK check" which was nice of them.
On the other hand, it was amusing to be pummeled in the face with rock and respond with a variety of options like "I sing calming songs" or "I use Absalom Lore to explain why they should no longer be here" or "I implore the Gods to speak sense to the spirits". But yeah, the need for a single skill is like gating for a specific level of training -- it makes it possible that the encounter cannot be run in a way that is fun.
I'm not sure it does any harm to ignore gating expertise levels, or to allow any vaguely useful skills for haunts.