I'm not surprised, I am surprised they've lasted this long. Old bikes, over priced, delivery and build issues, yes they'll appeal to the Norton enthusiast market but that isn't going to give you long term market.
Triumph on the other hand, most of their bike looks nothing like their classic stuff, competitively priced, so much bigger market, if they just sold the retro bikes like Norton they'd go the same way.
Norton learnt absolutely nothing from their original demise, sad but true.