So are you aware of what the actual sales trajectory was between 2008/9/10? My opinions are only based on the evidence I've found. The point is not that 2010 sales were "wrecked" but that the level of decline, inspite of a strong software line up doesn't paint a picture that Wii's later years could have been much better then what they actually were. Throwing in an extra title before Mario Galaxy 2 in 2010 wouldn't suddenly make a 5m difference in my opinion. So my question is what do you see as the reason for the consistent 5m declines (or what is the actual sales data)
And the later 2 paragraphs all center around whether Nintendo can release a game on 2 platforms. My point is that they can, a unified but scalable development environment is what Nintendo is currently doing and what they should continue doing with a Switch 2. The Switch's success should be partially be credited to the existence of the Wii U afterall, that soft transition (porting games over instead building them from scratch) is what I'm expecting, not a hard reset. I do not see a Switch 2 causing a significant disruption to games arriving on Switch. We're talking about titles early in development now, arriving in over 2 years time with less compromises. I don't see the threat to 1st party Nintendo games at all, I think people are actually more likely to buy said games if they are on a newly purchased platform. And I've mentioned why I think a new soft transitional platform 5 years in makes more sense then a mere SKU upgrade where said person is out of the echosystem 3 years later like the DSi XL for example.
Wii shipments for the fiscal years ending March...
2010: 20.54m (-21%)
2011: 15.08m (-26%)
2012: 9.84m (-35%)
2013: 3.99m (-60%)
Like I said in my previous post, 2009 closed out with high stock levels; 5.43m were shipped in January to March 2009, followed by only 2.23m in April to June 2009. If you account for stock levels and take away 1m from 2009 and add it to 2010 which is more representative of sell-through, then you are only looking at a decline of ~3m from one fiscal year to the next which is under 15%. Consequently, that would make the decline for 2011 bigger, but 2011 was already notably weaker in releases than previous years.
2007: Wii Sports, Wii Play
2008: Super Mario Galaxy, Super Smash Bros. Brawl (Japan, America), Wii Fit (Japan)
2009: Wii Fit (America, Europe), Super Smash Bros. Brawl (Europe), Mario Kart Wii
2010: Wii Sports Resort, Wii Fit Plus, New Super Mario Bros. Wii
2011: Wii Party
The biggest fiscal years strongly correlate with the release timings of the biggest Nintendo games. SSBB and Wii Fit spilled over into 2009, because it wasn't until March 2008 that SSBB got released in America while Wii Fit got a spring 2008 release in both America and Europe. 2010's big releases (WSR, WFP and NSMBW combined for over 80m lifetime); 2011's releases couldn't even combine for 30m (Wii Party, Super Mario Galaxy 2 and all the rest). 2012's release schedule was underwhelming; I already posted what Nintendo did during calendar year 2011. It's no secret that the Wii lived by Nintendo's first party lineup, so it shouldn't be hard to believe that it died by the lack of it.
Moving on to your faulty hardware logic...
Someone who buys a revision isn't necessarily out of the ecosystem only three years later. All it takes to retain is a next gen console that is worth buying and if Nintendo pulled that off, they would prolong the lifecycle of Switch and get all the benefits from next gen. Your logic is that a good five years of Switch are enough and that should be used to fuel into (presumably) five good years for Switch 2, but it would obviously be better for Nintendo's business if they get a good seven years out of Switch that fuel into another long lifecycle for Switch 2. There's no good reason to believe that they can't pull that off. It would actually be easier to go that route, because their best first party developers can finish their Switch games in late 2020 and throughout 2021 and then prepare to launch next gen games in late 2024 and throughout 2025 to get Switch 2 strong out of the gates. But judging from your post, you are actually talking about second string teams being supposed to prepare the launch year titles for Switch 2?
You also mentioned a cross-gen release strategy, but how do you get Nintendo fans to upgrade for processing power when they've not shown to go for that in the past? You hamper Switch 2 sales by doing cross-gen and that in turn would make the already reluctant third parties (they never have faith in Nintendo) hesitate even more. You'd invite a negative feedback cycle where lack of sales leads to lack of games which leads to lack of sales.
But above all, you assume that Nintendo fans would be tired of Switch in only two years from now. What is that based on?