No matter where you fall on the gold farmer debate ("they ruin the game" vs "they fill a need the developers refuse to acknowledge"), you have to stop and think about this particular premise. Lightspeed, a venture capital company that funds technology companies, asserts that any platform needs three critical elements to succeed.
- wide distribution
- application developers making money
- good tools.
Also, Blizzard already allows a certain amount of "external functionality" with allowing AddOns to function within the game, but even those had to be curtailed to prevent automation of activities intended for direct player involvement.
How do you see it? By shutting out gold farmers, who are making money by developing applications, is Blizzard setting themselves up for failure? Or is Blizzard protecting their wildly profitable venture from unscrupulous businessmen that want to profit from WoW's success regardless of how it harms gameplay?