I would imagine that the limitation for certain people who are actually fluent enough in Japanese just don't know where the hell to start, and only those who are at least a college student in programming or are very into it would know how to access the script in the first place, in a way making it more rare than the translator.
Now i am not fluent in Japanese at all, but heck at least i could try and make some sense out of it. I just don't know where to start and all that. I think that if at least someone knows how to access the script or images and know how to save it properly and an explain it well, there would be more upcoming translator in the game / flash game industry, even if it's just google translate.
But heck, at this point i'll take whatever i can get even if it is a badly explained way to do it. If it is comprehensive enough to make sense out of, i'll take it.