That's a little unfair. While one aspect of LDS preparedness might be their take on the rapture and how that'll play out, their teachings on preparedness are not solely aimed at that one scenario to the exclusion of other more likely/immediate scenarios. They also don't guard their preparedness teachings and learnings for exclusive use within the church, it's all quite openly shared to all without any reciprocation expectations. That's admirable, IMO.
Also, as a concept the LDS take on rapture as a reason to prepare, is very similar to how 'zombie apocalypse' is used as an engaging concept to drive home very practical preparedness thinking, while at the same time being in itself patently absurd.
Myths and legends of old served much the same purpose. All these things are fantastic tools if applied appropriately, and don't require being taken seriously/literally to be useful.