I admit to using UML from time to time. I do so because a specific UML modeling tool may meet specific communication and data storage requirements I might have. UML tools, for instance, make for interesting “object databases”. I occasionally find the detailed grammar of UML helpful as a helpful guide for thinking through the details of certain classes of problems. I use extensions to the grammar frequently. As a generalized communication grammar however, UML is severely limited and should be ignored. The appropriateness of UML is not well understood by a significant fraction of practitioners and its over use is certainly counter productive.
I believe that modeling tools are useful but must recover from the UML disease that has infected them all. I have a specific evolutionary path in mind which I will write about in detail at a future time.
If you wish to improve the efficacy of communication of complex concepts between team members, I urge you to return to the basics of literature, philosophy, psychology, linguistics, marketing and art. At the very least, read Edward Tufte. The efficiency-through-standards argument of UML is a myth.