This is a really funny question. The whole question seems to arise from the notion that a play is "information".
I disagree with that. A play isn't information, it's
art. There's no "who's more to blame" in Streetcar. If you're looking for the Right Answer, you're going to be frustrated. Williams quite deliberately left Streetcar ambiguous. It's one of the qualities that has had it endure as a work of art. You'll find that no two productions are identical, ever. Different directors will be emphasizing and de-emphasizing different things. Different actors will be making different choices with their characters. The message, in every single production, will be different.
When you read a play, it's like looking at the frame of a building that's being built. The structure is in place, but you have to fill in the blanks in your mind. It's not until a director and a company of actors applies their talent and craft to it that it becomes something with a message, meaning. Often when you read a play, you perform these interpretive functions in your own mind, but if not, you're reading something that's basically lifeless.
That's versus a novel or short story or, in some cases, a poem, which are meant to be read off the page. A prose writer just has a lot more WORDS to create the scene with, and the form is intended to be lifted off the page straight into the mind. One could argue that the same interpretive process is happening when reading prose fiction, but I'd say there's a lot more "author's intent" available when reading a completed work rather than instructions for mounting a production of something.
Some poetry, by the way, is meant to be heard (Langston Hughes comes to mind), and some is meant to be read off the page. Imagine a reading of e e cummings. "A leaf falls!".... massive applause.
