Terry Teachout asks the right question: "why are America’s best regional theater companies not as well known as our museums, symphony orchestras, and opera companies?"
For more, he points us to his freely available WSJ column on the topic here. Money quote:
When a museum in Los Angeles or Philadelphia puts on a major exhibition, nobody in the world of art assumes it to be second-rate merely because it doesn't travel to the Metropolitan Museum. The same thing ought to be true of a theatrical production. That's why the time has come for American playgoers -- and, no less important, arts editors -- to start treating regional theater not as a minor-league branch of Broadway but as an artistically significant entity in and of itself.
As I've said, we already have an American National Theatre, performing the finest plays by our finest trained artists, maintaining a national repertory. It's just not in New York, and not in any one city.
Just ask any good New York actor, director, or designer who spends most months out of the year on the road.