Well the same argument can be made ... I'm not American either, and it breaks immersion in the story less if my Japanese characters speak Japanese than if they sound like New Yorkers or like they're from Gone With The Wind. If they try and localize this stuff, it's usually done really badly as well, putting Japanese stuff in American terms that clearly don't fit what you see on the screen.
Anyway I'm hungry so I'm off for some donuts. Nothing beats a jelly-filled donut.
You are aware a LOT of the time the characters aren't Japanese or speaking Japanese right?
Madbull 34 is probably the only time I can think of where they gave the characters thick accents, with mildly ok voice acting, where it probably fit more then the Japanese.
Or another one is Hetalia where in the English version they attempted to give every country accurate accents when possible (I still prefer the Japanese one, if only because of the delivery of certain jokes get muddled in the dub)
Or rather... Japan never EVER attempts accents unless it is Kansai. Outside racism and the "Faux-Russian", I can't think of many Animes that attempted any sort of accent appropriate for the country. In fact I would go so far as to say that a lot of the time the localization often will go out of its way to give characters normal dialog (In fact subs often fudge details about the EXACT words characters are using just because it fits more... while the actual word is "ehh in the ballpark")
Or rather... Localization gets a bad rep when frankly bad localization should.
Compare Frog's Original Dialog versus his "Fixed Dialog". His Original Localized dialog quite handily characterized him as sort of a overdramatic blowhard which fit in quite well (What with him sequestering himself far away because of one single mistake he made... He kind of is a drama queen). Versus the "Fixed Dialog" (which is more of a direct translation) where he is, a person who exists! A lot of the time a direct translation just leaves a character, well... devoid of character.
Or I could point to Full Moon Wo Sagashite's horrible dub, but beyond that it kept all the character's names in tact, including the ones that are a mouthful in English. As well because the Japanese are more then willing to sort of "shorten names" (Takuto is often pronounced Tacto and Eichi is often pronounced Ech) but English isn't, it gives everyone long hard names. Or Freeken Sailormoon where in the manga they kept her original name... which is Bunny... Which is a horrible name. While in the English Localized Dub they gave her the name of Serena, which is just as symbolic as "Usagi/Bunny/Rabbit" but less stupid in English.
Other great Localization moves
-Changing Butz to Bartz
-Changing Tina to Tera (Bonus points for actually being MORE symbolic)
Frankly "Jelly Dohnuts" is the least of the translation oddities with Pokémon... or shall we forget the magic of them predicting Wendy's Bacon Double Cheeseburger?