Tell me you've never had kids...
You will "force" (let's admit it's not really force, but more nudging) children to clean their plate because they can't come back later and ask for food anytime they want. Learning to eat at fixed time, and to share a common meal (which is also a social bonding ritual), instead of expecting to be served at any time on a whim and live their life aloof of other's schedules, is part of socialisation and education.