Okay. What exactly is so "lazy" about sleeping late?

I’m really dying to know how not waking up at the crack of dawn makes a person lazy. Is it assumed that a person who sleeps late simply gets more sleep than people who wake up early?
I really have a hard time making a connection between laziness and the fact that some of us go to bed far later than others.
What about people who work the graveyard shift? I probably slept until 5 or 6 in the evening when I worked midnights… did that make me inherently more lazy than someone who goes to work at 9am?

Enlighten me. Please.