It just seems to me like a lot of Nintendo hardware simply looks better in silver and it's a good medium between going overly colorful and toy like but being black/white which is kinda bland. This is also much easier to instantly distinquish from the original Wii:
This photo is a mockup of a single screen 2DS, but the author, TheCongressman1 has also made a silver model to the right. I think it looks much nicer than the black models.
The silver GameCube was always by far the best model color IMO, Nintendo made a mistake by not making this one the main model over purple or even black IMO.
The Platinum GBA SP is one of the sexiest pieces of hardware Nintendo has ever made to this day IMO.
I think Nintendo should go silver more often. It's generally suited them well.