Do you have a source for this?
Some accounts also get stolen with phishing methods or used with fraudulent credit cards, that incur chargeback merchant fees for Blizzard. The “paid” amount plus penalty costing Blizzard a lot more not to mention the damage the botters do ingame.
For example in video 2 I think they explain how botters make very cheap accounts not profitable for Blizzard at all in here (thanks to that poster btw for linking):
They used to be banned immediately in the past, and then the illegal workshops would continue to modify them until they slip through. It’s not like they will just say “ah my bot is gone I will now pack my stuff and stop botting forever” it’s a criminal enterprise that will continue to attempt penetrate the security systems.
Seeing the amount of allegations that GM’s are “outsourced (country)” or automated this would highly reinforce the arguments that the investigations weren’t done properly.
It is not mutually exclusive, they can and will do both. Infact, trading is when the tainted gold changes hands so it’s one of the big cogs that has been addressed.
For example in another F2P game Valorant & League this is explained in more detail why it is so difficult:
An ex-dev that worked at Blizz:
If you have any good ideas don’t forget to submit them through the ingame suggestion box!