Comment by dreinhardt

It matters because someone has to decide what A- and B-List performance means. And the performance ceiling will shift if people put in 60 hours constantly. They will get more stuff done (assuming all else being equal) and soon your 40 hour A-List performance will have degraded to B level and now you’re either pressured in also doing the unrecorded overtime to get as much stuff done, or you are fired (you’re B-List now since someone is beating your performance by around 33%).