“Can someone please explain why pretty much every tzedaka organization is doing this?”
There are so many organizations “competing” for peoples money they always have to come up with something new. 25 years ago people were asking the same thing about chineese auctions (entice you with a watch or sofa to give tzedaka?). Then people started questioning the types of prizes offered at these auctions (tripes to E’Y, 100 grand cash). This is just the next evolution.