Bad decision making from Warner Bros., I would guess. If the studio wanted, it could just do standalones or one-offs like Joker or their animated projects without the need of a shared universe after poor leadership cut the legs off of the last one. I don't know if kicking the DCU into high gear so soon after the DCEU flamed out was a Zaslav move, one from De Luca and Abdy, or whoever, but even though the general audience probably can't tell an X-Man from a Peacemaker, it's still too early, I feel.
But who knows? Maybe Gunn will prove me wrong, but at the end of the day, his bosses are the higher-ups at WBD, and they've shown why we have no reason to trust them with the shared universe model.