IMO everyone doesn't need to buy equipment suitable for settling the northwest territories. Yes, a more substantial poncho would be my choice but a $.99 disposable unit can be quite useful. Good ones will see you through a sudden storm, perhaps two if your gentle with it. And a $.99 plastic poncho is a hell of a lot better than standing in the rain with nothing at all.

A bonus is that a $.99 unit is cheap enough to stock in considerable numbers and to hand out with no expectation of them being returned. They are also expendable. Use a few times and toss them. Not great for the landfill but not something you would use many of outside a mass casualty disaster.

Being disposable means that if they are contaminated by chemical fallout from an industrial accident, or other slime or toxic mess, you can save trouble by disposing of it instead off having to decontaminate it. It can make a lot of sense to wear a light disposable unit over a more substantial rain-suit and let the cheap stuff take the bulk of the insult.