A Wildcard is viewed as lesser bid because regardless of how many team are competing only 3 move on, while an at large/paid gets you a maximum chance of 10 teams moving on depending of the size of the group. That is not say wildcard teams aren't as good, not at all, it is just the acknowledgement that in larger size divisions you might only have a 10% chance of moving on from the wildcard while the same size division for an at large group(lets say for sake of argument 30 teams) would be 33% chance of moving on.