I think it's for a few reasons:

1. There's a trend  in which more then a few websites seem to mention NPD figures as being the only figures that count, while seemingly ignoring worldwide figures (perhaps for lack of data.) In such cases many people want the whole 'looking at the bigger picture' message to apply.

2. If MS could, they would proably mention worldwide figures and boast about them, yet outside NA their PR seems to remain far more silent then in NA. As such, posters question why the figures are limited to one region. The conclusion of this of course is because it puts MS in a better light.

3. Damage control. I don't understand why people feel the need.

But this is about NPD! It's US sales data! If you have no interest in US sales data then why visit an NPD thread at all!?

It's like going into a "Famitsu/MC thread" and saying "Japan is not the World"...or going into a "Others UP" thread and ask why they only mention sales data from EEMAA.

You don't call retarded people retards. It's bad taste. You call your friends retards when they are acting retarded.

ugh I think your missing the point here

NO ONE goes to NA charts and say hey this is not the world....lol It's about the misleading nature in which MS in perticular has been using NPD....you don't hear Ninty and Sony BS'ing about how dead MS sw sales in JP now do you? So yes people go into threads of MS PR boasting about sales and how they have outsold the competition, they tend to point out the irony so no need to get so worked up over it

first of all it wasnt an NPD thread, get your facts straight. It was a thread about a Greenberg trolling on twitter using NPD numbers.

 He used NPD numbers which in the overall total means nothing. Halo is huge in America, which everyone knew. If e had used the actual sales total, it would have been a different story.

Well, to be frank, America isn't America either. What you call America is only called United States for many others... ¬¬

"Why do threads mentioning NPD bring in people saying America isn't WW?"

If this were the case, maybe to present the bigger picture that tells a more accurate truth...?

I thought America took over the world. Guess I was wrong

Our Grand Empire had taken over 3/4ths of the world once though!

Nah that was Vgchartz that did it....