It's not! You just aren't looking hard enough. First, miniKanren interpreters have become vogue in some other languages. For example. Clojure has an embedded o

It's not! You just aren't looking hard enough. First, miniKanren interpreters have become vogue in some other languages. For example. Clojure has an embedded one: core.logic. Then here are some other full non-embedded languages, like Datalog and Mercury. There's not going to be as much variety as full-fledged general-purpose programming languages though because it's a more specialized domain with more restricted usage. And, well, Prolog is pretty standard. The question you have to get over is, if you need to use logic programming, why aren't you using Prolog or an embedded miniKanren interpreter?