Atkinson's impact on Broadway theatre in general was much greater than Horne's and I agree that renaming this particular theatre was a poor choice.
Although Horne had a huge hit with her Concert for the theatre, her career was largely away from Broadway and I wish there was a movie theater or a concert hall that could be named for her.
If we're renaming theatres, why not choose a black woman who had a real impact on Broadway, like Lorraine Hansberry, or someone who had a long career in the theatre like Jane White. Or even someone contemporary like Audra McDonald. Theatres used to be named after contemporary figures all the time back in the day. Ethel Barrymore opened the theatre named for her. So did Lunt and Fontanne, I think.