Half-agree with you, as none of the 18 positions are 'correct', but I don't know what you mean by 'useless'. Instead of generalizing I'll list my personal positions:

• KKK-style racist / politically correct liberal / "but there are scientifically proven genetic differences"

If I failed to notice that there are scientifically proven genetic differences I would be missing a far more important part of reality (evolutionary psychology and the huge effects of evolution in the last 20,000 years) than if I failed to notice that being a bigot was bad and impeded moral progress. That said, if most people took this position, it'd result in a horrible tragedy of the commons situation, which is why most social scientists cooperate on the 'let's not promote racism' dilemma. I'm not a social scientist so I get to defect and study some of the more interesting aspects of human evolutionary biology.

• misogyny / women's rights movement / men's rights movement

No opinion. Women seem to be doing perfectly fine. Men seem to get screwed over by divorce laws and the like. Tentatively agree more with third level but hey, I'm pretty ignorant here.

• conservative / liberal / libertarian

What can I say, it's politics. Libertarians in charge would mean more drugs and ethically questionable experiments of the sort I promote, as well as a lot more focus on the risks and benefits of technology. Since the Singularity trumps everything else policy-wise I have to root for the libertarian team here, even if I find them obnoxiously pretentious. (ETA: Actually, maybe more libertarians would just make it more likely that the 'Yeah yeah Singularity AI transhumanism wooooo!' meme would get bigger which would increase existential risk. So uh... never mind, I dunno.)

• herbal-spiritual-alternative medicine / conventional medicine / Robin Hanson

Too ignorant to comment. My oxycodone and antiobiotics sure did me good when I got an infection a week ago. My dermatologist drugs didn't help much with my acne. I've gotten a few small surgeries which made me better. Overall conventional medicine seems to have helped me a fair bit and costs me little. I don't even know what Robin Hanson's claims are, though. A link would be great.

• don't care about Africa / give aid to Africa / don't give aid to Africa

Okay, anyone who cares about helping people in Africa and can multiply should be giving their money to x-risk charities. Because saving the world also includes saving Africa. Therefore position 3 is essentially correct, but maybe it's really position 4 (give aid to Earth) that's the correct one, I dunno.

• Obama is Muslim / Obama is obviously not Muslim, you idiot / Patri Friedman5

Um, Patri was just being silly. Obama is obviously not a Muslim in any meaningful sense.

In conclusion, I think that there isn't any real trend here, but maybe we're just disputing ways of carving up usefulness? It is subjective after all.

Added: Explanations for downvotes are always welcome. Lately I've decided to try less to appear impressive and consistently rational (like Carl Shulman) and try more to throw lots of ideas around for critique, criticism, and development (like Michael Vassar). So although downvotes are useful indicators of where I might have gone wrong, a quick explanatory comment is even more useful and very unlikely to be responded to with indignation or hostility.