One of the most underrated actresses is Rebecca Luker. I'd put her on their instead of Idina Menzel. Luker was the ingenue of Broadway in the 90s, the Queen of Revivals. With a resume including Phantom of the Opera, The Secret Garden, Showboat, The Sound of Music, The Music Man, Nine, and Mary Poppins, I think she's a broadway actress who deserves more recognition.
That wouldn't be a big deal to me. She is one of the best actresses to ever grace Broadway and has a great voice. But I think it's Chenoweth's fan base and the fact that (minus Promises Promises) critics love her and she has Wicked.
I actually completely forgot about Bebe. I hate how Barbra got ranked so high because of one role when Bebe opened one of the most acclaimed revivals ever and has won two Tony Awards among countless other accomplishments same with Donna.
If Streisand is going to be included, why not Bette Midler? Midler didn't originate as famous a role, but she's played more engagements, even if most of them were revues.
And why NOT Judy Garland? Last time I checked, the Palace was still on Broadway.