Relevance is a read only query language, which limits it, but also makes it very useful.
Relevance has more in common with something like WMI than VBS, excluding the active parts of WMI that can make changes. There are other non-windows similar examples like OSquery, Factor, and others.
I actually quite like the distinction of having something that is strictly read only.
I also like the power that comes with relevance substitution, pairing the read only inside a script that makes changes in an action.