Reality is, these AI giants are here and they are using a massive amount of resources. Love them or hate them, that is where we are. Whether or not you accept the job with them, OpenAI is gonna OpenAI.
Given how much the detractors scream about resource uses, you'd think they'd welcome the fact that someone of your calibre is going in and attempting to make a difference.
Which, leads me to believe you're encountering a lot of projecting from people who perhaps can't land the highest of comp roles, and shield their ego by ascribing to the concept of it being selling out, which they would of course never do.