The censor politics are the reason why the Japanese put so much creativity into their adult videos. They can't show the genitals, so they have to focus on different things, like the actor's faces, different perspectives and storylines. That is also why so many fetishes are prevalent.
The only selling point for uncensored releases is that the genitals are shown. Japanese viewers aren't used to it, since uncensored porn is illegal and only gets underground distribution (or, in some cases, was made for export purposes in the first place). However, producers aren't going to put a high budget into something that they cannot sell properly, and underground sales are not stable.
1.) If you ask for uncensored videos in a underground store, chances are you will get a burned DVD-R with a photocopied cover. This is because movie studios manufacture the actual DVDs in international pressing plants (most commonly in Taiwan or South Korea). If a studio would press uncensored discs and attempt to import the finished products back into Japan, they would get fetched by customs. The responsible people would then be obligated to destroy them and be subjected to criminal charges.
2.) The studios that only sell their productions online are mostly small ones that can't afford the production costs for physical releases, so they only pander to a small audience. Since their budgets aren't high enough to rent popular actresses, they mostly rely on amateurs. They aren't financially able to produce videos like SOD, which is a major studio.