Obviously this isn't any sort of proof that working on FAI is irrational, but it does seem awfully suspicious that people who really like to spend their time thinking about ideas have managed to persuade themselves that they can save the entire species from certain doom just by thinking about ideas.

For what it's worth, I would personally be much happier if I didn't have to worry about FAI and could just do stuff that I found the most enjoyable. I also don't think that the work I do for SI has a very high chance of actually saving the world, though it's better than doing nothing.

I do consider the Singularity Institute a great employer, though, and it provided me a source of income at a time when I was desperately starting to need one. But that happened long after I'd already developed an interest in these matters.