Men who wake up early everyday with out a justified reason, why.?

So I usually wake up between 930 am - 1030 am on most days and I think thats a reasonable time to get up. I come from a family of morning people who are up by 5 am and they call me lazy and say I'm wasting half the day by sleeping in that late and I've just never understood. Today I had to wake up at 7 am because of work and thought "who would do this without a justifiable reason too.?" (IE work school court things like that)