The 2DS came out October 12 with Pokémon X & Y and only sold 30% of the 3DS family from October 12 to December 31st 2013.
The 2DS from January 1st to May 31st 2014 only sold 20% of the 3DS family, even though it was sold at $99 at all retailers long before that part of the year was over.
It has been estimated by many, that somewhere around 85% of 3DS owners ages 13 & up, use 3D on their 3DS/3DS XL.
There are only 2 places in the world where 3D has a problem succeeding: United States & United Kingdom.
Fact: 3-D gives way more clearity & anti-aliasing in image quality, then the crappy HD gimmick could ever accomplish at 4K HD 2D.
Fact: the 3DS has at least 120 million polygons with way more better Textures & Shader Abilities then the Wii.
Fact: the 3DS has somewhere from over 50 to over 100 shader cores.
Fact: the 3DS has a 1 GHz Micro GPU that won the GPU of the Year Award of 2010 (according to Nintendo themselves), underclock at 400 MHz by its 2-core 1GHz CPU with extreme efficiency that also focuses on more synthesis then any other CPU is known for doing, which might still be an understatement. The E3 2010 3DS only had a 2-core 268 MHz CPU that was only powerful enough to clock a 200 MHz Micro GPU @ 200 MHz.