I think the parent comment means that in "normal" circumstances the kids are not at home all day making it less of an issue. I don't think he meant that they will move out (plus in the area where I live there was a sharp rise in rents in recent years and it's now much more common for people to stay with there parents _much_ longer. Like meeting a 24 year old person living with their parents (again) isn't that uncommon. (Not that common either)).