For example, weapon-vs.-AC adjustments. In 1E it could at least be argued that whether the adjustments themselves were realistically representative or not, they were at least individualized to EACH combination of specific weapon and type of armor, whereas 2E (I suppose in an attempt to just simplify it so as to not require a full-page chart of optional fiddley bonuses) said that ALL slashing weapons, regardless of size, weight, length, etc. should have the same bonuses/penalties against a given type of armor. Piercing and bludgeoning weapons were similarly all categorized as ONE common set of adjustments and not individual to each weapon, making choice of weapon to use a key decision that changed with the actual armor worn by an opponent - often superseding the bonus to-hit from magical weapons. This eviscerated the whole purpose that 1E had in providing that big chart in the first place, for all weapons and armor class combinations individually. 2E designers seemed not to understand at all what that table was trying to do (even if it did it badly). Rather than make it work BETTER as an optional rule in accomplishing that original goal, they seemingly said, "It's simpler than 1E's full-page table and therefore empirically and uncontestably better for... whatever it is it's doing." I mean, I never personally liked WvAC and tried it and discarded it in both editions, but 2E's rule was awful compared to 1E's.