Isn't it a bit of a gamble anyway for the producers? They choose a group of celebs and hope some of them will become good dancers, some will become viewer favourites, some will be the comedy contestants etc. And at the beginning you never quite know which celeb will develop which way - that is what makes it interesting.
The BBC has followed the same formula that has worked in the past - a sportsman, a couple of former soap actresses, an older woman, a BBC presenter, an ITV presenter, a former politician etc. In previous years this gave us Natasha Kaplinsky, Mark Ramprakash, Chris Hollins, Kara Tointon, and yes, Ann Widdecombe. This year it just seems that, apart from Russell and maybe Harry, no one is really either developing as a great dancer or engaging with the audience enough to become a viewer favourite.