People hated the game because it tried too hard to be edgy, 30fps, terrible scripting even for Devil May Cry, invulnerable boss glitches, terrible lock-on, color coded enemies, game freezing and crashing, broken balancing with weapons, insufferable main characters, and rather than spoil it, there are a few choice cutscenes that sucked in particular like it was written by and angsty teen. That's the short list. The hair is just something that most people latched onto as a lazy argument against the above issues.
I'm more than happy to give out free samples of haterade, but there were a few things that I liked about the game. The animations of the attacks, pulling off attacks and combos were smooth, being able to weapon switch mid way into combos is something that should be implemented in future DMC games, and I liked the design of Vergil. How they structured the level score was on point too when it came to secret missions by having a special mission stage select once you found them as well as not making you re-find hidden orb locations.
I'd say this game is worth it at $10-15.