I haven’t forgotten that point, and I freely agree that GDKPs incentivize gold-buying, just as any game activity that requires gold incentivizes gold buying: Mounts, BOEs, etc. Banning things that require gold is not the solution, the solution is enforcing the rules.
Respectfully, you also cherry picked a portion of the article that comes after Blizzard’s initial reasoning (which I referred to as “Main Point”) . The sencence directly before yours is: “we’ve been concerned that GDKP erodes traditional guild and social structures that are in many cases the basis of our most fond memories of early versions of World of Warcraft.”
This is the stated reason GDKPs were banned. In my opinion the real reason was to quiet a loud minority of players who have never participated in GDKPs and mistakently think they are somehow hurting their gameplay. I honestly was like this before I tried them, and realized they are the best, and most enjoyable way to play the game.