Unknown, people are driven by their desires or natural tendencies. DmC and DMC fans tend to have some agressive behaviour between them because the human being nature works that way, mainly if they see the two series as opposing series (meaning if one of the two live, the other has to die in some manner, and this is kinda true to some extent). This is just how things are suppose to be, even if people do not make it clear on their statements or anything like this.
If people have a different opinion on the same issue, yep, people will argue. It's just nature that people will argue and that people don't like to lose or be seen as wrong.
I consider myself a very reasonable DMC fan and DmC skeptic, and as far as i been reading ToCool74 posts he looks like this too (and i think other users of this forum would agree with me), and even i myself already admited that if DmC has to be buried in order for DMC to return, i wouldn't mind it happening at all, but still i have the feeling that DmC fans deserve at least and ending to Donte's story, seeing that most of them liked so much the plot and world setting of that game.
I would like to see more of DmC, but I don't know if that will happen now considering sales. I don't want to see DmC cancelled or canned, but I'd be fine with that so long as DMC5 was made with Capcom taking lessons they learned from NT in how to make environments, characters and story.
But this passion some fans have to the old series ends up turning into hate to the new series and his fans because of what they represent, but the whole point here is to say: there are a plenty of people here on this forum who is able to be in control of their emotions and feelings and remain on this forum just to try and show their opinions in a reasonable and polite way, you should learn to recognize this kind of people to not unfairly accuse them, accusing someone of a thing that was not their doing is offense (and even a crime) too and even worse than criticizing someone's work in a "disrespectful" way.