Knights of Tezoth

I thought it only gave a penalty to hit chance...

To accuracy and evasion. In this regard, nothing much changes for anyone: everyone hits 10% less, but also dodges 10% less. In the end, the difference only favors Arandor, who has no penalty. But it cut crits for everyone... Except, again, Arandor.

Not quite. If evasion can't drop below zero, then there is a difference. And if the curse doesn't affect creatures. It also matters in attacks on pumpkins. For the most part, you're right, but there are a number of subtle nuances.