That... is entirely up for debate, since I could write a retcon fixing the storyline right now (in fact, I've written a vague outline of it in the past) and people will still disagree with it.
For example, people still can't accept the fact that Nero is Vergil's son even though it was in the novel and in the official DMC art book.
Not saying they're wrong, but maybe that's why Capcom decided to say "**** it," and just redo the whole thing over again since fans would have complained anyway, only on a (slightly) smaller scale.
And not even that much smaller, since the amount of people who complain about Nero being Vergil's son are more-or-less the same amount that complain about DmC.
That's my estimate from my own personal experience, anyway. I can't give stats because it would be nearly impossible to do. The best I could do is give a link to a thread complaining about Nero, and that just wouldn't be enough for most people.