Personally, I think Gethin, Kelly, Matt, Alesha or Letitia could win. I love John and he is doing better - if he continues to 'grow' then he too could be included in the number. Kenny has no sense of rhythm (something even he acknowledges) and it's difficult to teach that to someone. It's usually inherent or it isn't! Although he obviously is enjoying himself and that comes across well. Having no real favourites I don't mind who wins, just as long as they all continue to entertain.
Because this is, in actual fact, an 'entertainment' show. If it were merely a 'dance' contest, we would not be exhorted to 'vote for our favourites' and the numbers put up from Sunday onwards to vote for dances we have not even seen yet!
The fact that people who could actually dance have won over the last few years may also be down to how joyous and entertaining those dances were! (Because a really good dance is pure entertainment. Think Fred and Ginger, think Gene Kelly. They were not just dancers; they were also entertainers and their dancing was pure joy and entertainment).