I'm sure he's off on some other forum protesting that the cliff will come at 151 million. 

It did though; SNES and GBA were very successful consoles and among the highest selling ever at the time.

I think Nintendo will probably be doing really well this Gen. Mario seems more popular then ever. In fact the Mario movie is amongst the most streamed movies in the fist half of the 2020s.

Sure, but they sold less then their predecessors, and not by a small margin.

GBA was on an amazing pace but was killed early. Otherwise, it would have sold over 100 million easily.

The past is not the future. Part of Nintendo's problem is that they never stuck with a clear direction. They have a clear direction now. The Gamecube was not a clear successor to the N64, which was not a clear sucessor to the SNES, which got a delayed entry into the market because they wanted to ride the NES as long as they could (they were trying to make the SNES backwards compatible iwth the NES, which turned out to be unworkable). The Wii U was not a clear successor to the Wii, and it was not a product that anybody was really clamoring for.

Sony succeeds in large part because they have a clear direction of providing a mass-market console that appeals to both customers and third-party vendors. The one time they deviated from that strategy, the PS3, they opened themselves up to an offensive from Microsoft. With that said, they will never replicate the huge success of the PS2. Even the PS4, their comeback, still fell 50m units short. I don't expect the PS5 to sell as well as the PS4, but it will be close enough. I don't expect the Switch 2 to sell as well as the Switch, for the same reason that I don't expect Sony to repeat the PS2's numbers. The Switch was an extraordinary successful concept bolstered to exceptional heights by external factors that worked in its favor. The Switch 2 will not reach 150 million units, but there's no reason it can't reach 90-100m.

The SNES was the first time Nintendo had a significant competitor (in Japan, they also had the PC-Engine to deal with), and they ultimately prevailed over Sega and Hudson. They were arguably in a stronger position at the end of the generation than they were going in. Had they not gone out into the weeds with the N64, they would have likely fared much better and maybe held on to Square and Enix, which would have been a deciding factor against the PS1. 

The GBA got cut short by the unexpectedly overwhelming success of the DS, but it was incredibly successful.

Others beat me to it but GBA sold at an incredibly rapid pace and simply had a shorter lifespan due to the arrival of DS and PSP, while SNES faced much more intense competition than the NES and ultimately vanquished its rivals.

They were still both very successful systems.

Why wasn't the Nintendo 64 a clear successor to the SNES?

Why wasn't the Gamecube a clear successor to the N64?

Seems pretty clear to me.

This article from Gamespot correctly predicted that the Wii (then still called under it's codename Revolution) would win that generation, and even more to the point, it mentioned all the exact reasons WHY it would win.

So why post it here? Simply because it was meant to be an April Fool's article and it shows in the comments. A few believers against a horde of naysayers... until the date the Wii actually released, where people quickly flocked in to mock both the naysayers and the article's intention. And it's glorious to read them all!