Before Dylan, brilliant songwriters who were indifferent singers either wrote for the stage or churned out hits for others. Dylan persuaded a host of other singer/songwriters to go off on their own, and the stage suffered for fifty years.
Today, there is a renewed interest among established pop stars in writing musicals, which makes sense, for the following reasons:
1. There is a tremendous amount of money to be made in writing a hit musical. No elaboration necessary.
2. Songs in great musicals have a longer shelf life than the average pop single. Writing for the stage is both a tremendous challenge and a potential gateway to immortality.
3. Some of the stage shows of our current pop singers look like Cirque de Soleil, anyway. A Taylor Swift or Katy Perry show looks a lot more like a Broadway or Vegas production than Dylan singing in a coffeehouse.