that’s/it’s somebody’s loss
From Longman Dictionary of Contemporary Englishthat’s/it’s somebody’s lossthat’s/it’s somebody’s lossspokenEFFECT/INFLUENCE said when you think someone is being stupid for not taking a good opportunity Well, if he doesn’t want to come, it’s his loss. → lossExamples from the Corpusthat’s/it’s somebody’s loss• If they don't find me interesting that's their loss.