Actually the 3DS games I've worked on show that most people do play with 3D switched on (freakin love analytic data). And our numbers match up with other studios/games too. The 3DS is outselling the 2DS as well so to say 3D is dead isn't exactly true.
I play the 3DS XL with the 3D on full, except for Pokemon because they absolutely ruined 3D in that. Awful performance.
I just can't play successfully with 3D on the 3DS. I can ne re get the sweet spot to last for any duration of time, I like the effect when it works, just for me it works so little of the time.