Tino -
You're right, we should definitely have more secure IDs in general. It's way to easy to get fake IDs or perpetrate identity theft.
Anyway, (assuming IDs are relatively secure) you should at least have to show your ID at ticketing and to get on the plane. At ticketing you don't want someone else to pick up your tickets. At the gate if you don't the ID of people boarding you might as well not bother putting names on tickets. If you don't need to show ID then anyone can get on with anyone's boarding pass.
d