The WiiU was terrible idea from its name to the hardware. The WiiU sounded like an add on to the Wii than an actual new console. Nintendo also tried to pull the same stunt of selling last gen Hardware for a high price that they got away with the original Wii. Lighting didn't strike twice, coming out a year before the PS4 and the XB One with a machine that tech wise belonged back in 2005-06 was sheer stubborness.
The tablet pad device was an extremely weird choice since it drove the WiiUs price to an unattractive sum, and basically Nintendo never made a game that fully used the pad device to any innovative length, Star Fox was a letdown.
Nintendo was very clear and aggressive with the Switch's marketing. It was clear it was a hybrid console portable machine from the very beginning. The hardware while still a behind the base PS4 and XB One does a better job at closing that gap than the WiiU ever did (Odyssey at glorious 900p could pass for an XB One game) and because it is a portable it still claimed the most powerful portable gaming machine ever marketing tag thus justifying the price tag. The WiiU didn't release with a killer app, but the Switch had BotW which effectively had the same effect TP had a decade prior on the Wii ( Beloved Franchise new entry, high metacritic scores, "Greatest Zelda of all time" buzz from a lot of critics) it was a must have game for a cool new device.
Nintendo pretty much pulled out of the home console business and released a successor to the 3DS without telling anyone, thus effectively consolidating their efforts to one system. I would say that they did learn from their mistakes ....sales don't lie.
