I suppose the point I was trying to impress with my original post was this:
I personally do not believe that Blizzard had or has any malicious intent when they designed World of Warcraft to be able to use addons.
I do believe that they wished to give the mmo public a game that was a bit more player involved on a level not yet widely available, albeit knowing with some certainty that it would result in a hit game for them.
The simple fact that no one is forced to create an addon, nor use an addon, but an option of the game, not only in all probability will never change, (it is now the defining attribute of a 5 year old mmo) is a clear indication of any addon authors choice to freely add to the game and then freely share this addition.
In all honesty, not one addon (in its original form) would be able to be used outside of Blizzards game, so for Blizzard to incorporate something freely made/shared for the game they own, was an action that was not unforeseeable.
Every addon author made a choice to tinker with World of Warcraft and then share it with a community that loved using the additions to World of Warcraft, all without ever demanding that Blizzard hire them for their time and work, or acknowledgment of their ideas.
I am still unclear as to what the authors are upset over when Blizzard incorporates the additions to World of Warcraft.