This kind of attitude just sends the wrong message, devaluates everyone's work by subsuming it to mere tallies, and just outright crosses everyone, obliterating trust and turning it into a culture of fear. Turns out quite a bunch of us aren't efficient at all before 10AM because that's how our circadian rhythm is, yet it's viewed as laziness to come mere five minutes late as we're supposed to show up at least an hour earlier, preferably two. Net result, actual work is hardly done during this forced downtime, and reluctantly so afterwards. Everyone is just pretending to comply in order to bridge the impedance mismatch. As a result, everyone gets increasingly tired fighting their natural rhythm, and slowly growing bitter with each day passing as we witness ourselves wasting everyone's time.
Software development and engineering is a highly mental, creative process. We are not laying bricks 8 hours a day, we have to find and build new solutions to new problems, one by one. This process cannot be shifted, sliced, rearranged at will because it's not mindless, numbing, robot work.