I'm surprised you would say this, as it is the exact opposite of my experience as university teacher. I think we should teach concepts, and concepts appear much more crisply in small and focused languages. I think students gain more from being exposed to specialised languages than to more muddled multi-paradigm languages. For example, functional programming is much clearer in a language such as SML or Haskell than in Scala or F# (although the latter isn't that bad), because you can actually teach the whole language without any part of it muddling the concepts. Similarly, I would rather teach object-oriented design and implementation with, say, Smalltalk than OCaml.
Now, industrial usage is a different matter - here I have no problem with multi-paradigm languages.