C5 launched the show with the intention of it essentially being "young and sexy". Unfortunately for them, the winner of CBB was not Amy, Kelly or Lucien, but instead Paddy - the 52 year old man. In this series of Big Brother now, Aaron is the oldest housemate in there and he looks set to win so far and they're probably annoyed by that because they need someone like Alex, Jay or Louise to win to prove their point that the public like the young goodlooking housemates. It's a bit awkward for them if the oldest housemate in both series ends up winning.
Of course there's the issue also with them owning The Daily Star and them needing people to fill in the pages. I've yet to see a semi nude photoshoot of Paddy appear in the Star but you can guarantee there'd be loads of Amy if she won!