Well I guess maybe you shouldn’t use it then?
I’ve use these (or similar) for years.
Jamb nuts are used in machine tools, shock absorbers, electrical connections for winches, car alternators, etc.
If the item pictured is like the last ones I purchased and are currently in service it is a bolt head captured in plastic with two nuts and washers and a lock washer. The use is to tighten the two nuts against each other with two or occasionally three ring-terminal lugs between, washers against the nuts. Mine are quite tight yet the stud itself will easily rotate a few degrees where the bolt head is captured in the plastic which is plastic because it is an insulator.
If these terminal studs or their multi-stud busbar relatives are inadequate for your installations the split bolt connectors mentioned will perform the same duty, require two wrenches to tighten, but split bolts neither have mounting capacity nor are they electrically insulating without multiple wraps of tape with perhaps large heat shrink over that for DC.
Both will work for their intended uses and if installed adequately and safely. Calling either one junk isn’t useful.