You are only going a single step into this analysis. It's because the company chooses to run "a little hot" setting up the circumstances for 23M7. The root cause has nothing to do with pilots. The company exploited 23M7 and then negotiated it's expanded use. They chose to design schedule coverage around their newfound win and... consequences. Add in their batch size choices and PB day consent choice and you no longer have people readily available or willing to come in on off days. Commuters can be farmers too and probably had more OBWS experience than the masses.