I can't think of rational arguments, even steelmanned ones, beyond those Holden already gave. Maybe I'm too close to the whole thing, but I think that when viewed rationally, MIRI is on pretty solid ground.
If I wanted to make people wary of supporting MIRI, I'd simply go ad hominem . Start with selected statements from supporters about how much MIRI is about Eliezer, and from Eliezer about how he can't get along with AI researchers, how he can't do straight work for more than two hours per day and how "this is a cult". Quote a few of the psychotic sounding parts from Eliezer's old autobiography piece. Paint him as a very skilled writer/persuader whose one great achievement was to get Peter Thiel to throw him a golden bone. Describe the whole Friendliness issue as an elaborate excuse from someone who claimed ability to code an AGI fifteen years ago, and hasn't.
Of course that's a lowly and unworthy style of argument, but it'd get attention from everyone there, and I wonder how you'd defend against it.
I think I'm basically prepared for that line of attack. MIRI is not a cult, period. When you want to run a successful cult you do it Jim-Jones-style, carting everyone to a secret compound and carefully filtering the information that makes it in or out. You don't work as hard as you can to publish your ideas in a format where they can be read by anyone, you don't offer to publicly debate William Lane Craig, and you don't seek out the strongest versions of criticisms of your position (i.e. those coming from Robin Hanson).
Eliezer hasn't made it any easier on ...
I'm giving a talk to the Boulder Future Salon in Boulder, Colorado in a few weeks on the Intelligence Explosion hypothesis. I've given it once before in Korea but I think the crowd I'm addressing will be more savvy than the last one (many of them have met Eliezer personally). It could end up being important, so I was wondering if anyone considers themselves especially capable of playing Devil's Advocate so I could shape up a bit before my talk? I'd like there to be no real surprises.
I'd be up for just messaging back and forth or skyping, whatever is convenient.