Those are isolated screw-ups, though. Be a hero long enough, and situations will go out of control no matter.
Babs has a long win history that balances out the scales with regards to her screw-ups. Steph really doesn't. Whereas Babs has helped save the world, the best Steph has ever done was beat a disciple of Shiva, and even for that she needed help. Comapre that to her worst, and...