This might be a side effect of searching "top 15 3DS games" and going from that list. Most of them are filled with JRPGs, and JRPGs on the 3DS surely do love to use the chibi artstyle - the 3DS can't handle that many polygons at once, so simplified models make sense, and a chibi artstyle fits the genre and most of the target audience.

But there are plenty of counter examples of games that might not make the list, but have their own style. Though yes, most will have simplified geometry. Let's see:

• Monster Hunter 4 Ultimate
• Resident Evil Revelations
• Metroid Samus Returns
• The Legend of Zelda: A Link Between Worlds and The Legend of Zelda: Ocarina of Time 3D
• Star Fox 64 3D
• Zero Escape: Virtue’s Last Reward.
• Super Street Fighter IV: 3D
• Metal Gear Solid: Snake Eater 3D
• Gunman Clive
• Donkey Kong Country Returns 3D
• Rayman 3D

I agree, such a weak console nowhere near the glory of DS.

That's a good point. Must be the low resolution. Have you tried Xenoblade Chronicles 3D? I'm curious to hear what people think about the style of that game on the New 3DS