People with the means of fully funding their kids' private educations (even if they've "saved up") don't tend to have student loan defaults by definition, so I

People with the means of fully funding their kids' private educations (even if they've "saved up") don't tend to have student loan defaults by definition, so I don't see how that's even relevant. If even a plurality of parents in America could afford to do that, we'd live in a different world.