I wasn't one of the downvoters, but I'll hazard a guess.

• pursuing personal-level solutions for society-level hazards is highly inefficient.

Viscerally for me, this immediately flags as not being right. I might not understand what you mean by that statement though. It's very difficult to make an impact on the probability of society-level hazards occuring, one way or the other, so if you think there's a non-trivial chance of one of them occuring a personal-level solution seems like the obvious choice.

• I assumed, perhaps wrongly, that that was a given on this site, given previous discussions here. There's probably an argument to be made that all such actions are merely purchasing fuzzies and that protecting yourself is purchasing utilons, but I'd like to think that we're better than that.

I think you're significantly overestimating the uniformity of LW readers. The high-impact posters seem to have similar ethical views but I imagine most of the readers arrive here through an interest in transhumanism. On the scale from pathological philanthropists to being indifferent to the whole world burning if it doesn't include you subjectively experiencing it I bet the average reader is a lot closer to the latter than you would like. I certainly am. I care on an abstract, intellectual level, but it's very very difficult for me to be emotionally impacted by possible futures that don't include me. I think a lot of people downvote when you make assumpions about them (that turn out to be incorrect).

That being said, I don't have a problem with anything you wrote.