I also want to let everyone know that these are only my opinions and in no way am I correct in what I`m about to say, however I just wanted to leave my opinion of this whole plot based on my assumptions and thoughts. You may agree or disagree but in no way am I saying that I am right in anyway as these are based on what I have come up with using my ideas and personal assumptions to critique this plot.
You may also leave opinions to agree or disagree what I`m about to say as I`m always open to free discussion
In my opinion I think the author of Vampire Knight took a huge twist towards Kaname`s side throughout the plot for a certain reason. It wasn`t because she did it out of her own selfish ideas but it was because the fans in Japan voted on it. http://www.crunchyroll.com/forumtopic-200867/japan-vk-popular ity-pollconfirm
Here is the proof of the popularity vote of Vampire Knight characters in 2008 of Japan and Kaname ranked first overpowering the other characters. Now of course your thinking, "why on earth would she allow fans to control the way she wants the story to be written based on a popularity poll?"
This was around the time when the author was still developing the plot of Vampire Knight at that time and I think this also attributes to the fact that in order for her to gain more popularity of the series or to make it blunt "reap in more profits" then it already was at the peak of 2008, she decided to please her fans of Japan who at that time really liked Kaname and decided to turn the plot towards Kaname`s side instead of writing out a well written story. In doing so she left out a lot of great character development in most of her characters and lots of plot holes that could have been covered instead of focusing mostly on Kaname and Yuki.
A lot of people internationally out of Japan really liked Zero so why did Japanese fans go for Kaname? I think this has to do with the fact of the reality of the culture of Japan in that men seem to be more reserved and less expressive of their point of views especially in romance. The fact that anime is like a dream like world that can allow girls of Japan to dream or hope for a guy who will be their perfect shining armor or that the man will be kind, gentle, or maybe even express their feelings in a more expressive way. Adding the fact that Kaname had both the looks of a bishi and the personality of a gentle, mysterious, and romantic aura of that kind of guy gave him an extra boost of votes. This made Kaname very appealing for girls of Japan who dreamed for this kind of person. As for Zero who unfortunately fell in second place of Kaname the fact that he was at times really cold and less compassionate towards Yuki throughout the series made him a lot less favorable towards the girls of Japan and made him seem like a very cold person throughout the story (not blaming him for this though as this was his personality as a character that Hino Matsuri created). Not to mention Zero was kind of a sad and depressed kind of guy in the series as a whole which of course was not helpful at all for him to gain more votes. So in that sense Kaname had a clear advantage in winning over Zero by over 242 votes in the popularity poll.
Of course things might be different now but I`m looking at this in the point of view of the year 2008. I am not trying to accuse the author in any way of ruining the whole story by pleasing just her fans in Japan but this is my point of view of how things seemed to have gone for Vampire Knight and of course you are free to disagree with me in what I just wrote. I`m not hating this series but this is what I viewed in my opinion and of the way I analyzed it to be.
This opinion probably has a lot of flaws (I know) and may not be accurately correct.
So what are your opinions in how this plot turned out this way?
