I remember hearing that the management of the show isn't exactly easy to work with, and that may have been a factor as well. They may have asked the submissive ones back. What else would explain why they asked back Jason Tam, easily one of the worst actors currently working on Broadway?
Fosse, Tam is FAR from one of the worst actors working on Broadway. And he's an amazing dancer, probably the best male dancer in that company. So that's why he was asked back...because he's talented.