Showing up on time for work/school/etc., early in the morning, is a sign of grit and determination. It's virtue signaling, from the Before Times when "virtue signaling" wasn't right-wing dogwhistle for "I resent anyone who puts in effort not to come off as a bigoted asshole". We live in a society, which judges us according to ancient agricultural-society standards according to which those who sleep in late when there's chickens to be fed and cows to be milked are lazy; and the health benefits that accrue from such signaling (i.e., the ability to feed yourself and your family and secure a more comfortable life for them) outweigh the health deficits of getting up early itself.