Writing things in Vimscript makes for easy and entirely reliable deployment. Ruby requires a +ruby build and Ruby to be installed, but at least avoids some of the warts of Vimscript, while still being as simple as "put it in and use it". (For myself, I'd prefer not to depend on Ruby, or even Python, though it's a much safer bet.) Any plugins in C require a compilation step before you can use it.
I was maybe unclear, but I was regretting that a fuzzy find for opening files was not part of the vim core. It seems to be a generic editor feature that could benefit everyone.
