There are people still posting to this day about not being aware of how you pay for the M50; despite a decade of advertising and huge signs beside the road. So its really not that implausible for there to be people completely unaware of the NPPR.
In Ireland we haven't even moved all property to the bloody land registry (the site I am actually talking about in Dublin is "registry of deeds". We have a big stack of paperwork tracing the path of ownership going back a hundred years or so. It should have been all registered decades ago.
It's night and day how the two systems operate.
I was actually paying the NPPR for residential property that was habitable and rented out, but it never crossed my (or my brother's) mind to pay the NPPR for a property without a toilet, kitchen, windows, running water or electricity.