I think this is a sign of a throw-away society (with the ability to buy very inexpensive goods) and a side effect of airline luggage fees. Yes, they may not be technically throwing things away, but they are saying "We bought these things and they aren't even worth bringing home to us." Things like clothes, shoes, umbrella strollers sound like inexpensive items you buy at Walmart just for the trip and then leave behind because it was cheaper to buy them at Walmart and leave them behind than to pay to transport them to and fro.
I want to clarify that I'm not trying to sound judge-y at all here.
I just meant it very literally. That a $14.99 stroller could cost more than that to bring home or to bring to WDW in the first place.