Seatbelts tend to be held in with Torx-head bolts. Right bicycle pedals have left-hand-threaded studs. Spanner-screws are a standard you'll find drivers for in any good security or electronics/small-appliance repair set.
Odds aren't that far off that this screw was chosen for their blenders decades ago when this screw-driver was more common, and this one part was never updated as the design ... "evolved".
They didn't have to cut shit.