The judges decided that the deserving candidates for the 'wild card' were Sudha and Prachi. They are experienced and well-versed in the art of dance and they certainly know who deserves to be given a second chance. The winner needs a deadly combination of both talent (judge's points) and popularity (public voting). Prachi is definetely very talented and hardworking and so is Sudha. But apparently Prachi is more popular and so she came thru.
The others who were previously out of the game and were not included in the wild card were less talented and hardworking and were not really getting the hightest votes either. So there was no point in including them for the wild card.
Now it is left to see who strikes the best balance between talent (Judge's scores) and popularity (votes). After all, Negi ji is not a very talented dancer although he is very popular. So he may not last the next round of voting. However Sandhya, Prachi and Jai have a fair amount of both properties. Let's see who wins the race. All three are very good dancers, hard-working and are extremely popular with the public too.