DRM is useless, JAV studios should know that. Their movies are pirated on the same day, so the one who gets penalized is the one who wants to pay for the content, but with DRM-free downloads.
SLR is a good example that you can maintain a digital video business with downloads without DRM.
There are many of us who want to pay for JAV VR movies even if they are available for free pirated, but we need the downloads to be able to use our own players and max image quality, streaming is a disaster, as proven with R18.