total agree, I hope Clojure Spec will eventually be applied to most Core Clojure functions, and that information will trickle up to user defined functions. But thats only a hope, and possible based on my limited knowledge of the tool.

However, aren't most languages with the best errors messages Static and Strongly Typed?

My point was more that I think Spec was created to help address the issue. Not necessarily that it was even a good solution.