They use stolen credit cards to fund it. When the card-holder disputes the payment, the money is taken back from Blizzard as well as a handling fee, so Blizzard is out the cost of the subscription plus extra. Fact is, Blizzard loses money on these accounts. An account bought and paid for with a stolen credit card number is just as much a stolen account as one they hacked. Your belief of what the facts are doesn’t mean you are right.