The value of cost-effectiveness analysis (David Thorstad)

A few years ago, some EAs dismissed interventions like political action on the grounds that they had no detailed cost-effectiveness analysis.

Section 5 of this post wonders why some of these same people are now willing to promote longtermist interventions that have no such analyses (or whose analyses are, let's say, light on the details):

Did effective altruists discover some powerful new arguments against cost-effectiveness analysis that they were previously unaware of? Did they simply re-evaluate the strength of arguments against cost-effectiveness analysis that they had previously rejected. Perhaps. It would be good to hear more about what these arguments are, and where and when they became influential. Otherwise, critics may have some grounds to suspect the explanation for effective altruists' changing attitudes towards cost-effectiveness analysis is sociological rather than philosophical.

I'm one of the flip-floppers myself, and my own best answer is that I re-evaluated the strength of the arguments. But I completely agree with Thorstad that the whole situation smells like motivated reasoning.

I remember Holden Karnofsky once explaining it differently: he started out with a narrow focus because that's what was tractable at the time, and broadened his focus when he learned more. He never insisted on cost-effectiveness analysis from a philosophical standpoint, only a practical standpoint. (Apologies if I'm mischaracterizing his views.)

Interested to hear others' thoughts.