A rule-consequentialist would say, "Because if everyone followed that rule all the time it would lead to better consequences, on average, than if people tried to calculate the consequences of each individual action and act to maximize them."
Why would that lead to better consequences?
A rule-consequentialist could say, "Because people are quite bad at calculating consequences, especially in the tumultuous time before making a critical ethical decision. While we have had the time to think and properly calculate the hypothetical consequences of everyone following the rule."
I think that's exactly the argument Eliezer is making.
Put like that, I agree - I had a different meaning of "rule-consequentialist" in mind than you, apparently. (I'm not too familiar with the vocabulary of such discussions, sorry!) Thanks for clarifying.
Don't worry, like any academic field philosophy is filled with jargon, but knowing the jargon doesn't make you any smarter and not knowing doesn't make you any dumber.
Both you and Eliezer made good arguments and points, they just happened to already have a name in the philosophical jargon.
If you're interested, the Stanford Encyclopedia of Philosophy at plato.stanford.edu is the greatest repository of philosophical knowledge on the Internet.
Here is the rule: "Do no harm."
Why should we follow it?
A rule-consequentialist would say, "Because if everyone followed that rule all the time it would lead to better consequences, on average, than if people tried to calculate the consequences of each individual action and act to maximize them."
Why would that lead to better consequences?
A rule-consequentialist could say, "Because people are quite bad at calculating consequences, especially in the tumultuous time before making a critical ethical decision. While we have had the time to think and properly calculate the hypothetical consequences of everyone following the rule."
I think that's exactly the argument Eliezer is making.