because the creators of Last of us were giant SJWS, who wanted to be making movies in the first place. so the SJWS who only hire via chronism and political virtue signaling, had no problem hiring the actual creators.
Its like asking why so many failed webomics, or comics get optioned for movies/tv, like Nimona, she ra, etc. Either the comic was just a TV pitch in the first place, or they creator virtue signaled nonstop, had the right politics, so got optioned to work in movies/tv.
If the creator doesn't virtue signal, and they make something successful. well then that needs to be captured, and creator replaced.