Our minds are "general purpose" compared to, say, a chess playing computer program. But they're not necessarily "general purpose" in the most, well, general, sense. They're evolved with specific capabilities and talents that are geared towards helping humanoid, bipedal, mammalian creatures survive and replicate on a specific small blue planet, orbiting a particular yellow star.

As he pointed out in the article, there are examples of animals, like squirrels, demonstrating "intelligence" of a form that humans don't even remotely come close to having.

So, whether or not we have "general purpose mind" depends on how generally you define "general purpose." Which I think is actually an interesting point, in the context of what the author was driving at.