Engineers often design electrical products with the defect that you mention. That defect is to size the connecting lead of their device for the fuse size without thinking about the mechanical weakness of such a small wire size. That wire size should be used for telephone type connections and not for a power connection. That lead should have been at least a No.16 and not a No. 20. Had to repair a large new LED light fixture in a commercial building lobby the other day because an internal 22GA (I think) wire was broken during the factory assembly. That size wire had no business in that application. A little knowledge is dangerous.