Gaming systems sell because of price, library of games, and most importantly BRANDNAME. What's hot and what everyone else is getting. Word of mouth. What'ever goes best for you.
More than likely, the majority of PS2 buyers weren't buying it because it had " a great library of games" but because it's what their friends had, what was mainstream, and what everyone was talking about. People give way to much credit on why things sell because of gimmicks such as a random feature or a certain game. The fact of the matter ladies and gentlemen, is that the main drive to sales of any product is it's brandname and the appeal of that brand. When both sides that you described here Montana, your side and the Nintendo fanboys, come to understand this then you'll see why the Wii is selling well despite lack of games or why the PS2 sold so well despite all the features some of the other systems had.
Great systems don't sell well. Bad systems don't sell well. Great brands sell well. The other stuff just helps add on.
Explaining why Wii had such a poor launch and slow first year, and had to catch up to the rocketing PS3.
You (still) mistake momentum for "brand name." Gaming is a momentum based industry. Nintendo had to do something bold to launch quickly and gain momentum right out of the gate. They launched with Wii Sports, which attracted fringe gamers tired of the old type of systems, and at least until Wii Fit, were running on momentum since then. Sure, that momentum comes in the form of good WOM, but you can't equate WOM with branding. PS3 relied on brand name but only recently acheived anything resembling momentum.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.