This technology seems expensive. Plus is it justifiable for the next console like Zelda game too look similar to Wii U because Nintendo chose to make an impressive handheld with graphics like the Wii U but not higher?
The technology isn't that expensive actually. The Vita is already $199.99 and about half way between a Wii and Wii U. It's probably closer to the Wii U honestly.
By the time a new Nintendo handheld is ready to go, the Vita will be ancient tech, probably in the $129.99 a pop range.