This is what I always here, same with Anime. But I don't understand why this is hard.
Anime is a whole other matter. Japanese media companies are insanely risk-averse. If they know they can guarantee a sell-out run of 20,000 BD units at 6,000 Yen a piece for Anime X in Japan only, that's all they'll do. Won't run 25,000 units and hope for selling 23,000 at full retail.
Keeping with this, they also charge an arm and a leg to foreign companies to want to translate and distribute outside Japan. Since media costs are lower in, say, the USA, they worry that Japanese fans will wait until the cheaper foreign discs come out, since they'll all have the Japanese language tracks anyway.
Everything else you mention has to do with pre-existing agreements.