I think the public seem to be voting for people they like, rather than the best skater. It's easy to do it when everyone's a very similar ability, but I think this series sometimes (I can't really remember what the other series were like?) I've noticed it personally a lot, with people like Emily, Hilary (until now), and Sharron (although saying that, she has improved a lot) being voted in over people like Gary, Kieron and Danny, possibly because Gary especially comes across as just 'nice', with nothing hugely outstanding in some of his performances, and I don't know about Danny. I don't think he's amazing, but I think he's trying, he seems less arrogant lately, and I think there are people who deserve to be in the skate-off more than him.
But hmm, I don't know. The people I think deserve to be in the skate-off more have definitely improved, so maybe that's why they're being voted in.