Alright, straight off the bat let me say this is a well put together post and a cohesive set of arguments. I also want to point out that while I haven't played any of the Devil May Cry games, I've always thought Dante was a cool character, and I'm looking forward to the HD Collection.
Regardless, I felt I should weigh in on three of your points.
First of all, as someone has already pointed out, your mental attitude towards things changes as you mature and it's possible (likely even) that Dante may not be at a point where he's fully over what has happened. The change for me seems like the Dante you see in these short snippets are a Dante in the first stages of dealing with it. He's angry, and upset. He snaps because he's not in a good place. The Dante you see in the other games looks to me like he's worked past it. That's not to say he isn't affected by it, but he's sort of removed from it.
I prefer the type of marketing that Ninja Theory is trying with DMC. I prefer most story elements of games I play to be a surprise for me, because I want to consume that organically as I progress. Take for example Deus Ex: Human Revolution. Towards the very start of the game Adam Jensen is trying to protect a scientist when he's essentially brutalized to the point of death. Having already seen it in the marketing, when I came across it in the actual game it made more sense given the grounding of the world itself and the context, but it had lost the element of surprise that I knew would have really sold it. I realize that I might be an exception to the rule, but I'd rather be shown a lot of gameplay footage than key story moments.
The section on the developers being assholes is just plain poorly researched. You say the developers believe DMC fans are responsible for Enslaved sales as a fact, whereas it's an opinion piece by a third party that pulls no quotes from the developer. I should also point out that PR companies are not as closely affiliated with the developers as you assume. They're hired by the publishers, who want to get the word out about their product. In addition, you claim that NT threw fans to the ground and hurled insults at them at every chance whereas the only article you linked to that was the developers talking was them saying that they've been working closely with Capcom Japan to figure out the character designs. In fact, they even said that it's their job to make you feel like it belongs in the DMC series. That's not a developer that doesn't care. That's a developer that's going out on a limb (along with Capcom Japan, who you really need to include in your grievances) and who admits it. It may not look like much of a DMC game now, but wait until you play it they're effectively saying.
I guess to illustrate my example here, I want to bring up Wind Waker which had fans everywhere crying blue murder about what they were doing to Zelda. When the game actually came out, it was an extremely fun game that kept the essence of the franchise but moved it in an entirely different direction.
I feel that I've rambled for long enough now and my post seems to be getting less and less focused so I'll wrap it up now.
