Yeah the japanese censoring is just because of the weird leftover law unfortunately, and no japanese porn producer dares to challenge these laws by releasing something uncensored. I think the censoring of genitalia just became accepted as some form of culture as well. Like its THE trademark for any japanese porn nowadays.
Some people actually like the censoring, since it leaves room for "imagination". I can kinda understand what they mean, but i also wish to see everything sometimes.
This must suck especially for Hentai producers, since they fully animate the vaginal, anal and blowjob scenes only to have it censored before it goes to the public