A transcript (a) of Ben Hoffman in conversation with a friend.
Relevant excerpts:
Mack: Do you consider yourself an Effective Altruist (capital letters, aligned with at least some of the cause areas of the current movement, participating, etc)?
Ben: I consider myself strongly aligned with the things Effective Altruism says it's trying to do, but don't consider the movement and its methods a good way to achieve those ends, so I don't feel comfortable identifying as an EA anymore.
Consider the position of a communist who was never a Leninist, during the Brezhnev regime.
...
Ben: Yeah, it's kind of funny in the way Book II (IIRC) of Plato's Republic is funny. "I don't know what I want, so maybe I should just add up what everyone in the world wants and do that instead..."
"I don't know what a single just soul looks like, so let's figure out what an ENTIRE PERFECTLY JUST CITY looks like, and then assume a soul is just a microcosm of that."
OK, the issue here is you are assuming that metrics have to be the same in moral philosophy and in cause prioritization. But there's just no need for that. Cause prioritization metrics need to have validity with respect to moral philosophy, but that doesn't mean they need to be identical.