[Bozos of Bones]

Scimitars are wider along it's slashing side, meaning when it hits a material face on, it has a good backing to withstand the blow and not break or bend. But when hit on the side by something heavy or strong, it can break on occasion.
If you just leave them somewhere to rust out, a longsword will become unservicable(if old and rustable) whereas a scimitar can still be used to cut a few people before it breaks. New weapons aside, as new longswords don't rust and new scimitars will bend rather than break. In new conditions, a cutting side of the scimitar against a cutting side of a longsword, the scimitar has a better chance of not breaking because it is wider at the end of the blade.