U completely ignored what I said. We have no idea if Nintendo handhelds are more popular simply because they are handhelds or if it's due to other factors like price or game selection.
If 3DS & Wii U launched around the same time, at the same price and with all the same games than its very likely sales wouldn't be in such a huge favor for 3DS. Instead of outselling Wii U by over 5:1, it may be more like 2:1 or 3:1.
That's something Nintendo needs to try before completely cutting off one side of their hardware. If NX Console sells 30 million & NX Portable sells 70 million than keeping around a console variant would definitely be worthwhile.
If the Wii U ran games just slightly better than the 3DS, I think most people would buy the portable 3DS. What's the point of sacrificing portability if its the same games with roughly the same graphics.