You're comparing a man who makes odd faces while singing to a woman who has admitted, then denied having mental issues?
Let's be honest, being under the pressure of the show is bad enough for fully fit people (and I have my doubts about a couple of the ones that are through already), but imagine putting that poor woman through? When the Jedward-style backlash happened (and let's be honest, it would have happened), I'd be very worried she would not be able to deal with it, and have a SuBo or Nadia BB style breakdown.