My graduate program did not teach UML, but I did learn it during my undergrad program. It was a relatively small part of the major software engineering course. It introduced the idea of formally specifying software, and it forced me to reestablish, visualize, and otherwise integrate what I was simultaneously learning about things like interfaces and inheritance. It was presented as an educational tool and not at all that we would be using it in industry. Far from useless or out of date in an educational context.