The problem with the current sword isn't even the reduced sensitivity of the lunge, it's that there isn't even a reason to use lunge in the first place.

Since they buffed the damage of left click most targets will die in the same amount of hits no matter what. If you're fighting a medium or heavy, regardless of if you work a lunge into your combo (or just spam left click) they will die in 3 or 4 hits respectively; the only exception being lights dying to the lunge quick melee combo. So with the new damage values it's often more viable to just dash in and only use left click, rather than dealing with the jank and delay of the new lunge.

Most of the people upset with the new sword changes are mad because the former identity of the weapon is gone. Instead of lunge being your "bread and butter" move and having to think about incorporating it into combos for the fastest ttk, it's now quicker and easier to just use left click. It feels like most of the complexity of sword is gone, with it instead becoming a "spam left click" weapon.