I'm not buying the whole "don't complain, it's free" thing. I download tv shows, movies and western porn, all for free, and nobody ads watermarks or ads to those. So why should I put up with it in case of JAV.
Luckily there's enough stuff out there that isn't made unwatchable by this crap, even though it does sometimes mean missing a movie that looks otherwise interesting but can't be found in a clean version.