These are all people who could make good money anywhere. Few are presumably there solely because it's the best paying job. Part of it is certainly identity, Ope

These are all people who could make good money anywhere. Few are presumably there solely because it's the best paying job. Part of it is certainly identity, OpenAI or $hot_startup sounds way cooler than Microsoft to a lot of people. And part would be wanting to work at a startup and not a legacy SaaS company and all the baggage that entails. Whatever carve-out they were going to get, there's now way you'd be as unconstrained working at MS as you would at OpenAI. It's precisely because the money isn't that important that a lot would have probably bailed if they all were absorbed into Microsoft.