darquegk, your logic is flawed. In one single episode of MODERN FAMILY, Jesse Tyler Ferguson has been seen by more people in one hour on the small screen than he will have ever have accumulated in a lifetime of theatre performances. If a "theatre star" gets a recurring role on a hit TV show, their career is SET. In the world of "celebrity" they will ALWAYS be known for their film/TV work by more people who would recognize them for their theatre career.
If you show a picture of Jesse Tyler Ferguson to all of your non-theatre friends and ask them why he is famous, they will tell you that he is on MODERN FAMILY. No one will know that he was in SPELLING BEE or his other theatre work. Same with Lea Michele, et al.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle