See, even a game like Bible Black is only selling 10K units a year after its release in English. And BB is a very big title in America: so much so that sequels were made based off of the strong sales. It might have sold 25-30K units by now.
Thing is, it sells for half the Japanese typical asking price. So that’s the equivalent as if it had sold somewhere between 5 and 15K units of a typical Japanese game.
Compared to a Japanese game, this is nothing special. And this is one of the highest profile games ever released overseas: it has a popular OVA, and is actively being pushed as being linked in that way. And with that kind of strong brand, the game can’t sell enough to even approach Japanese sales figures, even ignoring cost difference.
GIven this, it is easy for Illusion to assume the US market is irrelevant to it. There is a lot of historical precedent in this area as well (many of the very early translations were of high profile games; they bombed in America.) And since they’re pissed off at us, there is no reason at all for Illusion to swallow their anger and get involved in the market. Sales would need to be very much higher. While this will probably happen eventually (total size of potential market of rest of world vs. Japan only is so much bigger), it will take a lot of time for a viable market of that size to develop.