It appears to be a human-centric classification scheme.

Yes, that's the point! We're humans, and so for some purposes we find it useful to categorize superintelligences into those that do and don't do what we want, even if it isn't a natural categorization from a more objective standpoint.

I read the essay you linked to. I really don't know where to start.

Now, we are not currently facing threats from any alien races. However, if we do so in the future, then we probably do not want to have handicapped our entire civilisation.

So we should guard against potential threats from non-human intelligent life by building a non-human superintelligence that doesn't care about humans?

While dependencies on humans may have the effect of postponing the demise of our species, they also have considerable potential to hamper and slow evolutionary progress.

Postpone? I thought the point of friendly AI was to preserve human values for as long as physically possible. "Evolutionary progress?" Evolution is stupid and doesn't care about the individual organisms. Evolution causes pointless suffering and death. It produces stupid designs. As Michael Vassar once said: think of all the simple things that evolution didn't invent. The wheel. The bow and arrow. The axial-flow pump. Evolution had billions of years creating and destroying organisms and it couldn't invent stuff built by cave men. Is it OK in your book that people die of antibiotic resistant diseases? MRSA is a result of evolutionary progress.

For example humans have poor space-travel potential, and any tendency to keep humans around will be associated with remaining stuck on the home world.

Who said humans have to live on planets or breathe oxygen or run on neurons? Why do you think a superintelligence will have problems dealing with asteroids when humans today are researching ways to deflect them?

I think your main problem is that you're valuing the wrong thing. You practically worship evolution while neglecting important things like people, animals, or anything that can suffer. Also, I think you fail to notice the huge first-mover advantage of any superintelligence, even one as "handicapped" as a friendly AI.

Finally, I know the appearance of the arguer doesn't change the validity of the argument, but I feel compelled to tell you this: You would look much better with a haircut, a shave, and some different glasses.

Healthy superintelligences execute god's utility function - i.e. they don't value anything apart from their genes.

Superintelligences don't have genes.

I think your term "God's utility function" is a bit confusing - as if it's just one utility function. If you value your genes, and I value my genes, and our genes are different, then we have different utility functions.

Also, the vast majority of possible minds don't have genes.

I am unclear on how this story is contrived. There are vast numbers of business with terrible externalities today; this is deeply related to the debate on climate change. Alternately, we have large cutting machines and those machines don't care whether they are cutting trees or people; if a wood chipper could pick things up but not distinguish between which things it was picking up it would be very dangerous (but still very useful if you have a large space of things you want chipped).