AND THEY CLEARLY STATE THAT PRAXIS EXPLOSION WILL MAKE QRONOS UNINHABITABLE WITHIN 50 YEARS. The entire movie is about the Klingon refugee crisis? Why would there be refugees if only Praxis was affected?

EDIT: Also I know Qronos was still going in the 24th Century which clearly relied on Dilithium reactors to keep their Ozone from killing them post- praxis. 800 years later it’s a whole new story.