Reason to learn propositional & predicate logic
I tend to like Unification and anything related to it. If you don't know propositional &amp; predicate logic, then you are skipping the basics of logic. If you have an interest in anything listed, then it would be like having an interest in math and skipping addition and multiplication. Logic is not just for AI.

As a practical answer, remember the Intel floating point problem and how you never see them anymore? Thanks to the use of theorem provers they are a thing of the past. Remember the Microsoft blue screen of death. Thanks to SAT solvers, model checking and other logic based solution, they are an endangered species.