The first was never a game. It was just a tech demo. Secondly, it's far less technically impressive than the actual reveal. I feel bad for you if you honestly believe the tech demo look better. It's so lifeless and serves Twilight Princess HD.
The actual game looks a lot more lively - the color, the design, the animation all **** on the tech demo.
Anyone saying the 2014 version looks better or is more desirable in terms of design is a liar or just a straight up fool.
It looks MUCH better. Look at Link's model and the spider. Very simplistic. Not much work was put into it at all. The new design is bold, full of personality, and eye catching.
Even from a technical standpoint, Zelda U beats out the Zelda tech demo.
It's a change in art style, not necessarily a graphical downgrade.
This video spills a lot of tea on what's going on in the world we saw:
Excuse the dire voice, but as you can see the entire world is reacting to things in a realistic way. I know the sony stans are too busy popping their bussys to the Fly that was on Drake's face in Uncharted 4's trailer, but surely they know that realistic graphics are not the only way to show off power and fidelity.
You can have different art styles and still have just as good graphics.
It's obvious Nintendo changed the artstyle to a cel-shade look in order to make the game open world.
If the new Zelda game's graphics were the same in the OP, we'd have around half the size of game area to explore (since increased textures etc take up more space on disc) due to Wii U optical disc only supporting up to 25GB.