I legitimately don't understand comments that dismiss the pursue of better compensation because someone is "already among the highest lifetime earners on the planet."
Superficially it might make sense: if you already have all your lifetime economic needs satisfied, you can optimize for other things. But does working in OpenAI fulfill that for most employees?
I probably fall into that "highest earners on the planet" bucket statistically speaking. I certainly don't feel like it: I still live in a one bedroom apartment and I'm having to save up to put a downpayment on a house / budget for retirement / etc. So I can completely understand someone working for OpenAI and signing such a letter if a move the board made would cut down their ability to move their family into a house / pay down student debt / plan for retirement / etc.