This is false, the most powerful system (or close) always wins given enough time.
This is why Dreamcast died, Saturn, Jaguar, 3DO, they all died because they weren't powerful enough. They came out early in a generation, and more powerful consoles eclipsed them.
This is also why Xbox beat Gamecube even though Gamecube had a HUGEEEEEEEEEEEEE software lineup advantage (I remember Nintendo fans telling me over and over at the time, Xbox was dead as soon as Mario came out, as soon as Zelda, as soon as Starfox, whichever, they were wrong every time).
Also, if you say Wii won even though it's less powerful, it really didn't. The PS3 and 360 are more or less the same console, with mostly the same games. The fact they split the HD market doesnt matter, any more than if the hypothetical apple wagglemaster took half of Wii sales and say, PS3 was the only HD console and "dominated" the market. Combined, the Ps3 and 360 are beating the Wii very easily now. More homes own a HD console, and they buy far far more software, than Wii hardware or software (and the gap is growing very fast lately, in most markets they are outselling Wii at least 2-1, 3-1 in software).
This is also why Ps3 fans are obessed with proving that Ps3 is more powerful than 360, and why most of their posts are about graphics, how much better than 360 supposedly Ps3 exclusives look, etc. Because they know how important it is. If it wasnt important, then why are most PS3 fans post across the internet about PS3 exclusives games supposedly great graphics?
Also, most people say N64 was more powerful than PS1. It wasnt, so stop that right there. PS1 could process more polygons than N64 and thats technical fact.
The only more powerful console that didn't win was Xbox, but it would have won if that generation had gone on forever, and moreover it did much better than expected, and it beat the Gamecube which had every advantage (price, software, brand recognition) except one, power.
Also, people saying the Genesis was more powerful than SNES are wrong. The SNES had more colors (256 colors onscreen versus 64 for Sega), mode 7 scaling and rotation, and far better audio. The colors alone made SNES games look much better than Genesis ones. Just look at Donkey Kong Country, that game was considering amazing at it's time almost as good as 32 bit games, and there was nothing like it on Genesis. Genesis and SNES were very similar in power it's true, that's why they sold similar, but SNES gets the nod.
Neo Geo clearly was the most powerful, but come on. The games cost $200. It wasnt reasonably priced. Lets not be ridiculous here. Stay within reason.
Put it this way, if power didnt matter, there would never be new consoles. Why wouldn't Sony just stay with the Ps2?? Why did they bother making PS3 at all??? PS3 lost billions but Ps2 hardware was highly profitable. Because Xbox 360 graphics would have killed the PS2 eventually and everybody knows it! If you can understand that, then you can understand that power always wins, it's not arguable. If you think it doesnt, then why didnt Sony make the Ps3 LESS powerful than the PS2?? After all it would have beemn cheaper, and given it the best chance to win since most powerful never wins!!
(haha, that last was obviously a joke, yet is a serious question too).
Even Wii is kind of struggling now because of it's lack of power. We all know it gets zero third party support, and is struggling with a lack of longevity right now. Wii is a bit of an exception to the power rules though as it sold on a gimmick.
