I have the Ridgid BS1400 bandsaw from HD and that seems to be the correct assembly. In fact, mine arrived with the blade installed and that cover already in place as you described. The instructions for changing the blade include a step for removing the rear blade guard. While you may disagree with the design, it is not the fault of someone at the HD store putting it together wrong.
BTW, the brand name is Ridgid, not Rigid.