Racist Or Just Insensitive?

I have cable TV again, after two-plus years without it.  I must say the vast wasteland has gotten vaster.  More vast?  Well, TV's become much worse than it was two years ago, and it wasn't very good then.  It seems everything is some terrible reality show in the vein of 'American Chopper.'  You know, where the cameras capture some dysfunctional event in the lives of awful people, and then they go back weeks later and feed the poor saps lines to say to knit it together into a story.  The people aren't actors so their lines sound like what they are, people repeating back to the producers what they were told to say.  Nothing real about it.
  So I try to avoid it.
  While I have been watching 'Las Vegas Jail' - which is exactly what it sounds like - for the most part I've been watching the Science Channel or the History Channel.  Because Stephen Hawking isn't famous enough, he needs yet another TV show about the universe.  At least it gets me away from the terrible awful 'reality' shows that are all alike.
   But I've noticed something disturbing, and I can't decide if it's racist or just insensitive.  Right now I'm watching a program about the Mongol invasion fleet that almost put 100,000 warriors on Japanese soil.  Their own version of D-Day but 700 years earlier.  They're interviewing Chinese scientists and Japanese scientists, experts in their fields.  The historians and archaeologists are speaking in their native languages, and the show provides sub-titles.
  But they also provide English-language narrative, with an accent.
  That is, when the Japanese scientist is speaking he gets translated into English by someone with a thick Japanese accent.  When the Chinese scientist speaks she gets translated by someone with a Chinese accent.  What the hell?  It's not the UN, it's not live TV, this is a taped show.  They could just as easily have given the English voiceover to a native speaker, someone with no accent at all.
  Why do they feel the need to make translated words sound like the person speaking is a first-generation immigrant?  Is that important?  Will people not believe the Japanese scientist really is Japanese unless they hear a thick accent?  Do the producers think that kind of thing matters to American audiences?  Because it doesn't, and as a matter of fact it's distracting and more than a little insulting.
  Do other countries do this?  When they're interviewing an American on French TV, do they translate him into French with an awful American accent?  Does Chinese TV use atonal American inflections when translating a white guy?
   Why are they doing this?  Why?  Why, why why, why, why?
   Just when I thought I could stop hating people...