Or "worrying about this possibility would be a poor use of resources, what with the incredible urgency of creating AI before humanity wipes itself out - you've got to go with what you have", this being uttered by people who just basically aren't interested in the problem.

I think this is unfair. When I first encountered the problem of FAI I reasoned similarly, and I was very interested in the problem. Now I know this argument has huge flaws, but they weren't caused by lack of interest.