World of Warcraft Launch: November 23, 2004
Hurricane Katrina Formed: August 23, 2005
Notice how, Blizzard, while still a successful company at the time, were nowhere near where they are today. Also notice that the Pet store or anything like it (Money for in-game items) was nowhere near "out" at the time of the Hurricane.
More importantly, note that Blizzard is a company, not a charity, and while it is very generous of them to do things like this, it is in no way their obligation.
The answer is quite obvious, Blizzard are american hating commies, I mean thats the only explanation, right OP?
Infact, Blizzard as a company is simply a front for anti-American pro-Commie activities, their whole scheme is to get your money to fund the Chinese war machine through what they claim is for relief efforts.