I think Ankita was given preference over Krushna taking into consideration her wildcard performance as well as cumulative performances- cos she had performed very well in the previous weeks and attempted different and difficult dance forms. Yes, she did not get a 30 or even 29, but we have to also remember that judges had already declared by then that they would be stricter with the marking. (This was AFTER Krushna had gone) She got a 27 for doing a classical dance form Kathak, and that in itself speaks about how good she is as a dancer, and Madhuri in particular always appreciated her a lot saying she always sees herself in Ankita. She got 25 for Break even though choreography was all wrong.
Nevertheless, I think it would have been better to bring Ankita back through wildcard and stick to the original format of the show.