It's not a bad design from a functionality standpoint, but the controller cost over $170 and was a huge part of the cost of the system, which meant Nintendo had to cut corners elsewhere to keep the price at $350. The controller, while light and comfortable, didn't really feel or look polished like the Switch does. I know that seems minor but it's something people look at when spending that type of money.I agree about the marketing, but I really enjoy using the system. I think while there could have been a few improvements, that the system was extremely flexible, decently powerful (though obviously short of the consoles that followed it shortly after) and that the software lineup (other than being somewhat small) was extremely high quality. I still use mine a pretty decent amount.
I will agree 100% on the marketing (or lack of) though. You're completely correct on that part.
The Switch is basically what the Wii U aspired to be, it just wasn't really possible yet in 2012.