The preflight checklist covers setting this (and all other parameters) to correct values. Not only did the flight crew not do that, the statement by Emirates h

The preflight checklist covers setting this (and all other parameters) to correct values. Not only did the flight crew not do that, the statement by Emirates heavily suggests that instead of making people actually follow the preflight checklists (which cover many other safety-critical settings), they're relying entirely on the plane being left in the right state by the previous crew.