Zinjo, Mikeszeckly - They would look at the cost/benefit ratio. The time and cost of licensing subs or getting new ones done, adding them to the discs (timing etc) vs the sales from a few extra maniacs from America etc who want a subbed copy of say the Macross Movie on HD and have HD equipment. Also if they did their homework would realise a lot of fans already have the bootleg of and are happy with it..Be honest theres only going to be a few hundred extra sales worldwide at the most if they add subs. Macross just isnt a mainstream product..
The idea of setting up distribution in North America is also an expensive one. Hiring staff, getting an office, etc etc. All for a few products with limited mainstream appeal.