Indeed, the original intention of these loops is to give somewhere for the cars to be strapped down when shipping. ....
Hmm ... I wonder where this notion comes from.
Mercedes refers to this loop in German as "Abschleppbügel" in the spare parts list and other publications, photo legends, etc, that I have seen, or in English as a bracket for towing.
Now "towing" means towing while the car is rolling and not for "pulling" a vehicle out of a ditch, or to pull it up a steep ramp on a tow truck where all the weight on the bracket. Of course, once on a flat bed it could be used as an additional tie down but then just one tie down location may not be sufficient for safe transportation.