Hi Eric, thanks for sharing this, made me think differently, which is much appreciated. 
I’d like to comment on one point you made: “One can see repugnant conclusions pop up in the everyday choices of the movement: would you be happier being a playwright than a stock broker? Who cares, stock brokers make way more money, go make a bunch of money to give to charity.”

I have a personal, subjective example which contradicts your criticism of this idea. I don’t know how prevalent this single experience will be in others, but I believe this idea is worth pushing back against. 

I was a musician, which was my “passion,” but was extraordinarily unhappy whilst working as a musician. The poor financial prospects, difficulty in making ends meet, and requirement to piece together unpleasant part-time and freelance gigs in order to survive, and maybe fund the “fun” and more “artisically fulfilling” stuff once in a blue moon resulted in developing repugnance towards music entirely. Most people who pursue their passions risk this experience, as the success rate of all artists is infinitesimally low. Or, they often keep going, even though they don’t like it anymore, for any number of reasons.

Now, changing careers towards research/academia (which obviously does not have a reputation of being lucrative, but compared with what I made as a musician looks like a goldmine), I finally made the GWWC pledge, and net happiness has increased for myself and others: I’m happier because I can afford to pay for rent and food, and on top of that, can afford to donate as an EA. Other people are presumably happier because they benefit from those donations. 

On top of the EA donations, I do tend to do what you mention at the end of the blog. Especially as I have so many artist friends that I want to support. And that is extra (on top of EA donations). And again, increases happiness for myself and others, as well as hitting at this diluted, longtermism view you give, by, for example, facilitating art making (which artists get to enjoy, and then consumers of the art) in addition to saving lives. 

I’m not sure how useful this is or isn’t to you - clearly, we largely agree. I’m just adding a hint of perspective on this idealistic mention of “pursue your passion because it will make you happier,” which you describe as being a move which contradicts EA philosophy. Because, I believe the odds are that it actually won’t, and in many circumstances, one might actually be happier as that stock broker.