The old-style lid doesn't look like you could use it as a handle to pick up the oatmeal container, so people probably aren't inclined try it. People are probably more apt to use two hands to pick up containers with these old-style lids.
Design suggestion
The lid on the new-style container should not look like it could work as a "handle" to pick up the container. This might be done by:
Not making the center of the lid set down in the top of the container so deeply.
Removing the "handle" from the inside of the lid by curving the lip outward rather than inward.