While I agree that what @Pikachu6319 describes sounds unusual, be careful not to overstate your own case. The World Championships may be the highlight of the competitive season, but it is one tournament out of an entire year; the metagame fluctuates throughout. There was even a period when N wasn't Standard legal but was Expanded legal! As we can look up the most recent results easily and the results of the four highlight "Commemorative" World Championship decks fairly easily, let's look at those:
The first release of N came after the 2011 World Championship but N doesn't exactly have a new effect; Rocket's Admin released back in 2004 (after the 2004 World Championships), and its effect only differs in that a player could draw up to the number of his or her Prize cards. For our purposes, this isn't too relevant as it only matters for those few times when a player would not want to draw as many as possible off of this effect. So looking at the relevant World Championship decks again:
- In the Masters Age Bracket of the 2017 World Championships, seven out of the eight decks ran 3 N: no more, no less. 8th place ran four.
- Looking at the four decks selected for the "Commemorative" 2016 World Championship Decks, three out of four run only two N, with one running four.
- Looking at the four decks selected for the "Commemorative" 2015 World Championship Decks, one ran one, two ran two, and one ran four N.
- Looking at the four decks selected for the "Commemorative" 2014 World Championship Decks, all ran four copies of N.
- Looking at the four decks selected for the "Commemorative" 2013 World Championship Decks, all but one ran four copies of N, with the final running three copies.
- Looking at the four decks selected for the "Commemorative" 2012 World Championship Decks, each deck ran a different amount: 1, 2, 3, or 4 copies of N.
So what does this tell us?
- Looking at the four decks selected for the "Commemorative" 2006 World Championship Decks, one ran two, one ran three, and two ran four.
- Looking at the four decks selected for the "Commemorative" 2005 World Championship Decks, one ran one, two ran two, and one ran three.
What it does not tell us is, again, how things changed throughout the entire year. It does suggest that competitive decks are likely to run high counts of N but sometimes only a single copy will suffice, and there are formats where two copies were adequate for most decks. There are almost certainly several factors to consider, like the presence of VS Seeker, non-Supporter draw, etc.
I appreciate you taking the time to compile all that info. I understand that it doesn't necessarily tell us how things changed throughout the entire season. However, N is considered a "staple" Supporter, alongside Professor Sycamore and Lysandre (now Guzma). Regardless of how the competitive scene changes, we can look at the winning deck lists from regionals throughout the years to get a good idea of how many N each deck used. I'm not telling you to compile all that information, haha, but I think we can safely assume that N was used in 99% of decks, if not all of them.
I still think it's... odd... that supposedly almost every deck in Pikachu6319's area barely uses N. I could understand if he alone doesn't want to use it, but an entire area? Then again, we don't know how many people he's actually talking about. It could be 5 players for all we know. He could also be overstating things himself.