They could just track your IP via the game because you're still connecting to their servers..
Yes, but they think that by using the website it'll be easier to track hackers. In reality they're just ruining themselves.
Wanna know a secret? Combat Arms wasn't actually created by Nexon, they hired a bunch of game creators from different companies to work on this. Lucky bastards. Nexon themselves have no game creators, the different games with different graphics. Mabinogi was their biggest success because of the RPG style gaming and because of the graphics, then CA came along with better graphics and FPS/RPG type gaming. They don't make the games, they just put their mark on it and claim it's theirs so they make money. It's basically a win for them.