Nearly every cover shooter ever plasters waste-high walls everywhere with little effort made to disguise their purpose. It's not rare, nor is it intended as foreshadowing, it's just clarity of design.
In general, I don't mind them. Complaining about the aesthetic integration of waist-high obstacles in a cover shooter is like complaining about the practicality of air-brick placement in a Mario game. It's only an issue in story-driven games that are trying to be a bit more ambitious than Super Mario World.