OpenAI CEO Sam Altman is hitting back at Meta CEO Mark Zuckerberg’s recent AI talent-poaching spree. In a full-throated response sent to OpenAI researchers Monday evening and obtained by WIRED, Altman made his pitch for why staying at OpenAI is the only answer for those looking to build artificial general intelligence, hinting that the company is evaluating compensation for the entire research organization.

He also dismissed Meta’s recruiting efforts, saying what the company is doing could lead to deep cultural problems down the road.

“We have gone from some nerds in the corner to the most interesting people in the tech industry (at least),” he wrote on Slack. “AI Twitter is toxic; Meta is acting in a way that feels somewhat distasteful; I assume things will get even crazier in the future. After I got fired and came back I said that was not the craziest thing that would happen in OpenAl history; certainly neither is this.”

The news comes on the heels of a major announcement from Zuckerberg. On Monday, the Meta CEO sent a memo to staff introducing the company’s new superintelligence team, which will be helmed by Alexandr Wang, formerly of Scale AI, and Nat Friedman, who previously led GitHub. The list of new hires also included a number of people from OpenAI, including Shengjia Zhao, Shuchao Bi, Jiahui Yu, and Hongyu Ren. OpenAI’s chief research officer, Mark Chen, told staff that it felt like “someone has broken into our home and stolen something.”

Altman struck a different tone about the departures in his note on Monday.

“Meta has gotten a few great people for sure, but on the whole, it is hard to overstate how much they didn’t get their top people and had to go quite far down their list; they have been trying to recruit people for a super long time, and I’ve lost track of how many people from here they’ve tried to get to be their Chief Scientist,” he wrote. “I am proud of how mission-oriented our industry is as a whole; of course there will always be some mercenaries.”

He added that “Missionaries will beat mercenaries” and noted that OpenAI is assessing compensation for the entire research organization. “I believe there is much, much more upside to OpenAl stock than Meta stock,” he wrote. “But I think it’s important that huge upside comes after huge success; what Meta is doing will, in my opinion, lead to very deep cultural problems. We will have more to share about this soon but it’s very important to me we do it fairly and not just for people who Meta happened to target.”

Altman then made his pitch for people to remain at OpenAI. “I have never been more confident in our research roadmap,” he wrote. “We are making an unprecedented bet on compute, but I love that we are doing it and I’m confident we will make good use of it. Most importantly of all, I think we have the most special team and culture in the world. We have work to do to improve our culture for sure; we have been through insane hypergrowth. But we have the core right in a way that I don’t think anyone else quite does, and I’m confident we can fix the problems.”

“And maybe more importantly than that, we actually care about building AGI in a good way,” he added. “Other companies care more about this as an instrumental goal to some other mission. But this is our top thing, and always will be. Long after Meta has moved on to their next flavor of the week, or defending their social moat, we will be here, day after day, year after year, figuring out how to do what we do better than anyone else. A lot of other efforts will rise and fall too.”

A number of high-ranking employees who’ve worked at Meta followed up in Slack with their own stories about why OpenAI’s culture is superior. “[T]hey constantly rotate their top focus,” wrote one. Another said: “Yes we’re quirky and weird, but that’s what makes this place a magical cradle of innovation,” wrote one. “OpenAI is weird in the most magical way. We contain multitudes.”