I have no problem with him working hard - I don't think anyone has won this without working hard. I think the winner has generally been the person putting in the most hours per week (I'm sure someone knows for sure whether that has been the case every year). However, in each of those cases, the winner was also someone who forged a great relationship with their partner, which I don't see with Jason and Kristina.
We have seen many people succeed who are competitive, which is no problem so long as they are male.
And the winner is also someone who shows just how much they enjoy dancing and learning to dance. Again, I don't see that. Jason seems to me like someone who has set himself a challenge - "Learn to dance and win at doing so". It's just another job to him - one that he wants to do well at, but still just a job.