It is an undisputable fact that by far the biggest market for movies (including porn) is North America.
I am aware that most Asian countries have laws about peculiar laws about porn which require genitals and sometimes faces to be digitized so they are obscured into being semi-recognizable. They even do that with cartoons! (crazy!). If that is the way those countries want it, fine.
It's a blanket law AFAIK. No genitalia on live action and animated works. For some bara manga I've read, some authors have found creative ways to at least censor the penis by just using a squiggly or straight line.
What I don't get is why there are not undigitized versions of these movies. Obviously they have taken a lot of time to add the digitization to these movies which originally had no digitization. Why not market the undigitized versions to the North American market? I'm sure they don't add digitization to movies from Staxus or Helix or BelAmi or Falcon or Corbin Fisher or Sean Cody when they are marketed in their countries.
I think the Japanese studios aren't really that eager to export their works outside Japan, where they can be uncensored. I think movie and video distribution labels like Kitty Media would have to request the work for it to be distributed uncensored. If they themselves would go out of their way to export their works, we might already have an uncensored version of Boku No Pico. On the flipside though, I don't know if they import porn so I am not sure if censored version of western work are available.
Then there is the puzzle about sexually oriented video games. Almost all of them come from Japan, yet they don't bother to come up with English versions of them. Maybe the authors of that software are not aware of "Bing Translator"?
Most of them are doujin/independent works. They are mostly done by one person or by a small company and they sometimes don't translate their works because they don't know if it will catch on outside Japan. I'll probably list Danganronpa as an example of this. It got noticed when the original PSP game got a fan translation and now most of the games are translated for release in North America, and with English voices to boot.