On duty has a very high standard for vigilance and responsibility. The military punishes many things that civilians routinely do.
But work hard and play hard is the motto of many who risk life and limb in defense of a bunch of 'have no idea' civilians.
When grunts come out of the field, spend the night cleaning equipment and weapons for turn in, grab a shower and a few hours sleep they are ready to let it rip. It is PARTY TIME.
Perhaps you are confusing folks who's primary job is to kill people and break things with the clergy...