"Even the original parry from WAAAY back had some pentalty for not using a
shield, which seems to have dissappeared sometime between 1995 and like
2003..."
You're talking about how parry was supposed to work at half effectiveness if
one wasn't using a shield. Someone noticed that it was in fact working
normally regardless of shield use, and for whatever reason this lack of a
penalty became a feature instead of a bug.