Because the Nintendo Wii was quite less powerful than its two competitors (ie. the Xbox 360 and the PlayStation 3), yet outsold them by quite a wide margin, branding itself as the ubiquitous "casual gamer console" and "family console", many people today (especially younger ones) have got this impression that Nintendo has always been about content rather than technical specs, and that they have never cared about the latter, and that their consoles have always been "weaker" than the competition.
This is actually completely false. In fact, the Wii was the first Nintendo console that was significantly less powerful than the competition. Moreover, in all previous console generations Nintendo has always been about boasting about technical specs, and trying to out-perform the competition on that front. This, somehow, is actually somewhat surprising to these people. (And, on a meta level, the fact that it's surprising to some people is in itself surprising to more knowledgeable people.)
The original NES might be the sole exception in that it might not have been directly trying to out-perform its main competitor (the Sega Master System) in terms of hardware, but on the other hand it wasn't all that less powerful either, and didn't really have the "it's not the tech specs that matter, but what you do with it" mentality either, at least not yet. Nintendo was more like probing the ground with the NES, to see what sticks.
The SNES was clearly and unambiguously a direct response to the next-gen competitor console (ie. the Sega Genesis/Megadrive), outperforming it in terms of hardware in almost all respects, especially graphical prowess and sound.
The Nintendo 64 was also a powerhouse for its time (and, to my knowledge, the most powerful console at the time it was published). It was heavily advertised for its hardware specs, so much so that the fact that it uses 64-bit technology is right in its name. That's how much they advertised it for its hardware specs.
Again, the GameCube was also a powerhouse, outperforming its major competitor, the PlayStation 2 in terms of hardware prowess (perhaps to the surprise of many people who don't know this.) (Basically the only reason why the GameCube didn't become successful was because of Nintendo's stupid idea of using a custom data disc format that was very difficult and expensive to develop for, and severely limited the size of games. Thus not so many games were made for it, pretty much dooming the system.)
The Wii was, in fact, the first Nintendo console that did not actively try to out-perform its competitors in terms of hardware specs. (In fact, it's so close to the GameCube in terms of hardware prowess, and shares so much of its technology, that many people have called it just a repackaged GameCube with motion controllers.)
It was only at this point that Nintendo, deliberately or serendipitously (probably the latter), adopted the "it's not the tech specs that matter, but what you do with it" mentality, as a result of Wii's enormous success. (An argument might be made that it actually started a bit earlier, with the Nintendo DS, which was less powerful than its competitor the Sony PSP. But this was nevertheless well after the GameCube.)
They used the same mentality with the Wii U, which didn't pan out that well (although the reasons might have less to do with hardware specs and more to do with stupid marketing decisions.) We'll see how it goes with the Nintendo Switch (which, once again, has significantly lower hardware specs than its current competitors).