Who exactly was Nintendo's primary target audience with the Wii U?

[baloofarsan]

All of them (Nintendo, MS, Sony) targeted the same audience. Let's take a look what was trending the years before the start of this generation:
iPad was big and getting bigger. Siri was the new big thing on iOS.
So Wii U and DS4 has touchpads. MS settled with motion and voice controlls instead.

Motion controlls were big.
Just Dance sold more than ten million, Fitness games sold well (Wii Fit Plus over 20 million) To capture this audience, mostly girls - a "new" customer segment, would be a golden opportunity.

TV was becoming a thing for young people with streaming services and popular TV series (and sports). Apple TV had a slow start but others, with Googles Chromecast as the biggest contender, saw a market and so did Nintendo (TVii) and MS.

VR/AR was coming.
Nintendo missed this one but Sony was ready (always on light bar) and MS had the Hololens hidden in the basement.

Always online was a fact for all electronic devices. Steam was were games were going.
Nintendo improved their online and their eShop and brought Miiverse. Streaming was the sollution for Sony and MS had the power of "the cloud". It just turned out that game consoles was the only electronic gadget that was NOT going to be always online, at least according to angry forum dwellers.

Pachter and other analysts predicted the end of cosoles as we know them.