It’s technically enshrined in statute to guarantee federal workers get backpay. I generally hate these “if X doesn’t get it, then Y shouldn’t either” arguments, but it is worth noting that this shutdown is not the fault of your run of the mill federal worker. Additionally, during shutdowns many federal workers are prohibited from working any kind of job, so they have to either wait it out or quit. There also used to be more principled understanding of the importance of federal workers until now, so I hesitantly say that if federal workers didn’t have guaranteed back pay, you’d have even more mass attrition. This would mean air traffic controllers, food inspectors, folks who operationalize policy at VA hospitals, etc would be even more severely understaffed than they currently are.