This whole iconic/not iconic issue simply comes down historical context.
If you are one who is aware of the events/achievements from the past, then you know what Norton was back in the day, and it was indeed an iconic motorcycle brand.
However, if you are, as many young-ish folks today are, an empty headed, trend chasing snow flake, then the name Norton only represents a brand of anti-virus software. To be honest though, Norton has been out of the picture for decades. Before Donington, the last Norton motorcycle sold to the public in the US was in 1975. So you can excuse the current motorcycle community for not knowing that Norton motorcycles existed in the past, or that it was an iconic brand.