I wasn't making any arguments to the fact that SIAI is likely to succeed in saving the world or even that they are the best option for FAI. (In fact, I have a lot of doubts about it.) That's a really complicated argument, and I really don't have enough information to make a statement like that. As I've said, my goal is to make FAI happen. If SIAI isn't the best option, I'll find another best option. If it turns out that FAI is not really what we need, then I'll work on whatever it is we do.