Shoddy hit detection for one, and I honestly thought the reaction time from button press to actual animation just doesn't feel solid. But then again, I'm not a fan of PB much to begin with.
I've never really had an issue with either the hit detection or control responsiveness in any of PB's games. The player's attack animations aren't as quick as Ninja Gaiden's or Devil May Cry's but those games have much faster-paced combat in general. As for hit detection, it seems pretty accurate to me. The fact that you can't interrupt enemy attacks and/or not all enemies play hit reactions may make it seem like the hit detection is inconsistent, but it's working as intended.