I don't agree.
I actually think it could make a very good stage musical.
For me one of the problems of the film is that it is too Yentl/Streisand centered. It has more to do with glorifying Streisand and giving her die-hard fans something to gorge on then the actual telling of the story.
The story itself - which is rather engaging one, regardless of Streisand -would only benefit from more musical numbers for the surrounding characters.
My caution with this project is that it might end up Victor/Victoria meets Fiddler on the Roof. And not in a good way.
As for Streisand, there are a number of talented age-appropriate actresses with star-quality who could play this role.
What great ones do the less will prattle of