Because they say he's too soft.
"Ohh noooo! He's not a silent, anime trope! Ninja Theory's Vergil sucks! Help us! Help us!"
Seriously??
"No, forget character development. We want Vergil to be cool again. How dare they take away our shallow, one-dimensional character!"
This is the best thing that could have happened to Vergil. He has depth. He has charisma. He has conflicting emotions and feelings. This feels like a real person with a soul. That can never be considered a bad thing.
Being a cold, ruthless swordsman is fun for a while. But if you want your character to age well, if you want him to last, then the character needs to have layers. Complexity. Believable motivations. Without that, you just end up with... DMC3 Vergil.