But what if your personal value system includes wanting your day job---what you spend 40 hours/wk or more doing---to be directly implementing something you care about?
Sure, that's a selfish choice to some extent, but I think it's a reasonable one. Some people choose to live in one city over another just because they like it, or to work at Google rather than Wall Street because they like what they're building there more. Some people will pass up a job for one that pays 20% less, because it's building an exciting new app they want to help succeed. Wanting to work on a social-justice project just seems like a variation of that; it's quite common and natural for people to want their day job to be something they care about, if they have the option.
I think the argument as given also assumes that charities are currently operating optimally, and there's no room for improvement or disruption. If you applied the efficiency argument to startups in general, it would argue that you should work a well-paying job and pay other people to do startups. When would it ever be beneficial to do one yourself? Only if you think the market is not already efficient, and your personal intervention as a founder could change things more than working your current job and just funding startups would.
I think you're actually in agreement - if you can do more good via your day job than you could going out and doing manual labor, it's objectively better for the cause for you to do it via working more at your day job. It's just saying that it's silly for someone with a ton of leverage to abandon that leverage and volunteer as a manual laborer, rather than using the leverage to do a lot more good.
Sure, that's a selfish choice to some extent, but I think it's a reasonable one. Some people choose to live in one city over another just because they like it, or to work at Google rather than Wall Street because they like what they're building there more. Some people will pass up a job for one that pays 20% less, because it's building an exciting new app they want to help succeed. Wanting to work on a social-justice project just seems like a variation of that; it's quite common and natural for people to want their day job to be something they care about, if they have the option.
I think the argument as given also assumes that charities are currently operating optimally, and there's no room for improvement or disruption. If you applied the efficiency argument to startups in general, it would argue that you should work a well-paying job and pay other people to do startups. When would it ever be beneficial to do one yourself? Only if you think the market is not already efficient, and your personal intervention as a founder could change things more than working your current job and just funding startups would.