I would just love the option to be able to obtain purple puzzle pieces in a way that doesn't make them nearly impossible to find in North America without traveling 1000 miles to Nintendo World or around the world to Japan. NWNY is the only place where I've found purple puzzle pieces in enough quantities that allowed me to actually complete a puzzle.
I have unfinished puzzle after unfinished puzzle sitting on my 3DS with giant purple holes in the middle and minimal chance of ever completing them. It's not really fun anymore when you know that the goal is unobtainable.
Not to mention, even with 3 3DS's in our house, we have never received one purple piece as the random first piece. The purple piece idea was nice for Japan. Everywhere else, not so much.