Can't please them all.
For a large portion of fans, DMC should have stayed the same way with absolutely no changes at all. However, there would still be the terrible camera motioning, the fanfiction style story-telling (Then again every story in the world is a fanfiction of an original somehow), Dante acting like a bigger joke then before, and so on.
For the other portion, DMC needed to change with a new look on it. However that meant giving up the iconic white haired red coated one-liner hero for the black haired black coated witty emo punk anti-hero, change in the enviornment from creepy castles to modern mixed with european streets, and original DMC fans judging you and calling you an idiot or a dumbass for liking it, or worse. The same old "You're not a true DMC fan if you like this game." I hate that.