how people are raised is the best reference they have for issuing punishments to rule breaking so it's no surprise that japanese admins swing the hammer hard and without mercy on any issue no matter how small, especially with how their legal system operates. They could end it with just refunding crystals and exp, and deducting the price of those crystals from the offender's account, but instead it's "die, rulebreaker!"

personally i suggest to turn player into invincible from monster when they are in pvp

it is easier and less complicate and controversal ^_^