"Yes, I fully agree with what you write about Streep's suitability for Margaret Johnson and Blanche. As for the latter, this loss--for her and for us--is, of course, a direct result of an actor limiting her or himself to the movies, no matter how equipped (s)he is to do stage work. Streisand always wanted to play Rose? Why didn't she do it for even just a few weeks in an LA theater?"
Excellent point. Some actors have avoided doing live theater for specific reasons, but most of those reasons would not apply to a limited-run stage production which could then be filmed or recorded for viewing in cinemas or on TV.
Although, for that matter, I would imagine Streep has always had such popularity and clout that if she had really wanted to do a traditional theatrical film or TV movie of STREETCAR, she would have had no problem finding someone to produce it for her.