I do not think this is the correct way to understand the issue.
When my plays are produced by others, they generate a revenue stream. Why shouldn't I be entitled to a portion of it?
If my work is re-produced/re-tranmitted/re-purposed in new media that generate new income streams, why should I, the originator of the work, be left out of the process?
Don't I as a worker become aliented from the product of my labor when other people can make use of my work to generate income streams for themselves and not share any proceeds with me?
I have often argued that when an artist's work is up for auction, they should receive a portion of the proceeeds from the sale since it is the product of their work that generates the revenue stream. If Sotheby's can get a commission, why not the artist who started the process in the first place with her work?
Brian