It’s because it was an absolutely huge video game event that very rarely happens and especially not of that size. I don’t even live in America but nothing like that would ever happen here. It also happened on Nintendo’s first console which adds to the historical significance.
Zoom out 50 years from now. Hardly anyone is going to even care about most of the NES library, but sitting in gaming museums will definitely be a NWC telling the history of a huge gaming event. This is why people value it so highly.
Which other events have been as big and significant as NWC? I know of the Famicom one thanks to defaultgen but I’m not aware of anything quite as huge as NWC or the Famicom competition. Especially in the early days of gaming.
Also, it’s good to question people about why they think a certain way. It creates discussion. You don’t have to agree but at least we can have a friendly back and forth