I'm impressed to say the least.
They should have done it sooner, but I wasn't playing Aion at that time. Until my funds allow it, I'm sticking to private servers.
And I believe they didn't do the bannings sooner because they were doing the Vision trailer and fixing some bugs. GMs cannot do everything at once you know. Do you know how long it takes to find and make sure 16,000+ accounts truly botted?