It’s not what you have been led to believe.
Forum and/or Player input, or the existence of bots, or any negative effects to the game or its players didn’t have anything to do with the closure of the Auction Houses.
Let me tell you what really happened.
Here are some conversations about the subject from February 2014, starting with the inception of Account Bound items:
Q: So what is it exactly that BoA will achieve for Blizzard?
The sole purpose of BoA is to eliminate the third-party real money sales of virtual items created by Blizzard. The IRS wants Blizzard to track and tax these real money sales and profits, and with private users on the Americas server, Blizzard would have to provide sales transaction records, collect taxes, and make payments to the IRS on the profits of individual players and Blizzard as a whole.
The bookkeeping and data management nightmare, and the human resources and monetary cost of complying with this requirement is more than Blizzard cares to bear. That’s the reason they are shutting down the Auction Houses, and that is why all desirable items, including gold [and now everything except Common and Magic items, and Rare items that have not been modified in any way], will be account bound on pickup. This is also the reason for including the shutdown of the gold auction house. Gold can’t be traded.
Q: One could make a persuasive argument that they’re only focusing on the illegitimate.
Persuasive, but incorrect. BoA and the closure of the Auction Houses had nothing to do with third-party sites ruining anyone’s game, or even the impact it had on gameplay or players at all; it wasn’t done to improve the game or gameplay, nor due to pressure from Self-Found fanatics or the “Pay to Win” opponents.
It was all about minimizing Blizzard’s financial exposure to the IRS, and to the Financial Crimes Enforcement Network (FinCEN, for the black market real money sales of virtual items).
Q: I call BS. Source?
There are a number of regulatory publications, but you can start with the most important one:
https://www.fincen.gov/resources/statutes-regulations/guidance/application-fincens-regulations-persons-administering
The most pertinent part of this Guidance lies in the first paragraph, which in substance says that Blizzard is an MSB (Money Services Business) - an administrator, an exchanger, and a money transmitter - under FinCEN’s regulations, and therefore is subject to MSB registration, reporting, and recordkeeping regulations.
The issue is far-reaching, and the Financial Crimes Enforcement Network, a bureau of the United States Department of the Treasury, is not joking about it. Notice the publication date on the Guidance; March 18, 2013. Blizzard had one year to comply with the registration, reporting, and recordkeeping regulations, or close the Auction Houses.
And to save money, on March 18, 2014, they closed them.
As I keep saying, BoA and the closure of the Auction Houses were not about gameplay or gamers, it was all about reducing financial exposure for Blizzard and its shareholders.