The ironic thing, we are talking about non existing characters, they never had a real voice to begin with, so the excuse of it being the original and that makes them automatically better voices doesnt fly for me.
If most of the time is better is because the guys responsible for the thing are the ones who usually decide the voices they want, and if they are good at vision that voices and get good actors, it works perfectly...
But theres also the case were other countries have done fantastic dubs to the whole cast of a series (cartoon or videogame) that are at the same level or some time surpass the originals.
For example, lets see. A game made in Spain, like Commandos. So theres an american dub and a spanish dub, made exactly at the same time. Which one is the original there? The Spanish voices becuase the game was done in that country? But they arent really the original, because the american dub was made at the same time...
So which one is automatically the best there?
What about Bayonetta? A japanese game that came with an english dub, and didnt had a japanese one, even if the game is japanese, until it came to the wiiU?
And wonderful 101, same case as the Commandos example, american and japenese dubs worked exactly at the same time for a japanese game.
Etc...
And its a case of quality my friends. Even if I prefer to hear some japanese animes in japanese, other times I prefer its english dub, EVEN not being american (case in point, W101 american dub has a thousand times more personality than the japanese one, having played both). And sometimes I prefer the spanish voices to the american one. And other I love to play or watch that thing in two languages, becuase I think both are great. I like variety and quality, and IMO its better becuase its the original is closing doors for better things.
And wow, less than 1 percent over 50! Yep, thats the majority.....
No its really not, it half and half nearly exactly. So the best decision for japan here would be to give the option of japanese dubs or original voices, or you are going to segregate half your audience.