People being hacked since the last Server Check.

You can challenge it but you still signed it. I see nothing in NEXON's ToS that's unreasonable.

"Unreasonable" to a jury or judge is very different from "unreasonable" to a company that wants to be paid for nothing.
The client/service relationship has several implicit expectations from the public that can not be waived just because a business doesn't want to have to deal with them. It doesn't matter if purchase of NX is compulsory or not; Once it's purchased the issuing organization has a responsibility that's been purchased with the money they've been handed and no amount of legalese will free them from it any more than a bank can say "your deposit wasn't a purchase of anything so if someone else comes along and takes it from your account without your permission because we didn't stop them we don't owe you anything".

And reading fine print is irrelevant if the contract is written in such a way that is unfair or unreasonable. It's just as much one's responsibility to read a contract they sign as it is for someone to write a contract that wouldn't be nullified in court.

Particularly since the only way a company could enforce the terms in a contract is by taking you to said court in the first place, meaning if it's not enforceable and they can't scare you into doing it they'd have to pay to go to court to try to enforce the terms that would likely be nullified anyhow.