the wii u failed for many reason but the biggest was its name Wii U it confused the crap out of people for the longest time i thought it was a tablet for your wii and not its own new thing. The marketing also sucked badly with it so A it confused me and b didn't convince me to buy the thing i was confused about it was until the NX had been announced that i started asking for it but then I heard about the Switch and it was over its why I still don't own a Wii U.
I still don't believe that the name was its biggest problem.
If you have a good product, videos of great games will speak for themselves and potential customers will search and find the informations about the system they need/want.
When the Wii was announced Nintendo got ridiculed for the name at any corner... didn't hurt the sales.
The third and fourth iPad generations were called "iPad", not "iPad 3" or "iPad 4"... didn't hurt the sales.