Similarly, you could create a robot to watch movies for you or go on dates for you, but there'd be no point, as you'd be missing out on the enjoyment. The statement about whether something can be automated refers not to mere physical possibility, but to whether it improves your subjective human experience. Thus you can't really automate watching movies or going out on dates because you can't have someone else live life for you. The benefit you gain is all in the experience of it, not the accomplishment of it.
The mindless activities these MMOGs subject you to are all of the accomplishment variety. Those shouldn't even exist, but if they do, they deserve to be automated. Then people enjoy the experience of being able to engage in the non-mindless activities.
The amount of scripting WoW allows is trivial compared to what you can actually do.
Any computer game can be automated if you can implement an AI that is good enough. Saying that "any game that can be automated deserves to me" seems kind of silly to me.
Calling WoW a glorified Skinner box seems like a similarly useless thing to say. At that level of lexical precision, news.yc is also a "glorified Skinner box," as is driving to work in the morning and going out for dinner at night. I don't really see the point of the analogy.
It's easy to automate "various game activities," but certainly not all game activities and not most of the ones that really matter. It would be more accurate to say that there are some specific activities that can be automated, but the expense of that versus the reliability of a human operator is not worth it. MMOG environments are too volatile, even without considering admins.
Warcraft actually allows a great deal of scripting. Coming from a game like Everquest, the level of automation Blizzard allows is mind-boggling.