Nintendo only was able to sell a small number of WiiU's (13.6 million
IR Information : Sales Data - Hardware and Software Sales Units in a bit more then 4 years. That is a huge flop especially when you take in account that PS3 and Xbox360 user had a hunger for a new console. Nintendo was early but delivered a current gen console while most consumers where in the market for next gen.
Although the Switch is a bit more powerful it's not close to a PS4 or Xbox One and even these consoles will be replaced by a next step in evolution in about 2 years. It's not a contender to replace these consoles and it will be (mainly) another Nintendo software only console.
They could stop making consoles and produce their games for PlayStation, Xbox and mobile and be insanely successful financially. Nintendo has deep pockets but their investors won't tolerate another flop. In the end the ip's are strong and whatever the Switch will do, Universal will have a great partner with the Nintendo brand, nostalgia wise and for the future.