Tom, I can’t quite work out whether you’re basing what you say on actual information about how much SIAI is spending and what it’s doing, or just arguing on general principles that there’s always some point at which diminishing returns mean you should put your money somewhere else.
If the former, then (1) I think you’re focusing on specifics of the particular case, which seems kinda off-topic (I thought the point here was about how much sense it makes to solicit contributions from groups like “artists”, “women”, “people with PhDs”, etc., without having a specific plan for what sort of contributions you want from them), and (2) I don’t think it’s possible to make further progress with that discussion without having the actual figures, which I don’t.
If the latter, then you’re probably right, but the point at which it stops being worth funding something depends a lot on the specifics and I’m not sure what the relevance is here. I mean, did anyone claim that everyone ought to be donating exclusively to SIAI or anything like that?
(Perhaps the subtext is that you think SIAI isn’t a good thing to be contributing to at all. I’m taking no position on that, not least because I haven’t thought through the difficult issues involved; I thought the interesting discussion here was about the general issue, not the Singularity-related specifics.)