Whenever I see quotes about "kids these days can't do X", I'm always skeptical.
You remember the kids in your class that were just absolutely, indefensibly stupid? These quotes are probably talking about those specific kids. I seriously doubt out of a class of 30 kids, all 30 of them couldn't stack the blocks. It was probably the 5 kids in the class that are just stupid, and every class throughout the history of time has had those stupid kids, and always will.