Calling it the "hardest decision of [his] career," Straley explained the move in a post on Naughty Dog's website: "I'm leaving Naughty Dog with the strongest team it's ever had, and that's saying a lot. But more than the talent, it's the people that I'll miss the most. The work culture at Naughty Dog is about getting out of your seat and solving problems together. It's what has allowed me to build so many friendships and gain so much respect for this stellar group of people.
"I get it--'it's just work'--but when you spend as much time as we do together, in the pressure cooker of creative work and deadlines, you really get to know a person. And I've had my share of difficult and humbling moments. But having the privilege to see people grow beyond their concept of what's possible for themselves technically, creatively, and personally has been the most rewarding aspect of my job and continues to motivate me to do the same. I'm so proud to have been a part of this team. I can't wait to see what they create in the future."
He goes on to thank a number of individuals by name, including Amy Hennig and Neil Druckmann, with whom he worked on the Uncharted series, as well as former co-president Christophe Balestra, president Evan Wells, and co-founders Andy Gavin and Jason Rubin. Straley had been with Naughty Dog for 18 years, having started there on the excellent Crash Team Racing back in 1999. More recently, he serves as the co-director on Uncharted 2 (with Hennig) and Uncharted 4 and The Last of Us (both with Druckmann).
Straley and Druckmann were not originally set to direct Uncharted 4 but were brought on partway through the project after the completion of The Last of Us. Notably, we learned late last year that Straley would not return for The Last of Us: Part II, instead opting to take time off from the studio.
His blog post doesn't mention what's next yet, simply saying, "As I close this chapter with a heavy heart and an appreciation for everything Naughty Dog has done for me, I open the next with an excitement to continue the journey into the creative process. I don't have anything to announce just yet, but I look forward to the discovery and to sharing it with you all soon."