>>23 It does seem that the Japanese usage is broader. In Japan, you have baseball otaku which would be an anathema on English chan boards.
it being obsessed with certain things and related fields
I'd add that this obsession is based in an interest and fascination for their own sake. So professional analysts and researchers might be obsessed with something because they get something useful out of it like money or position. Whereas an otaku is obsessed for the sake of the obsession, even if that comes with some side benefits.
It does seem that the Japanese usage is broader. In Japan, you have baseball otaku which would be an anathema on English chan boards.
I'd add that this obsession is based in an interest and fascination for their own sake. So professional analysts and researchers might be obsessed with something because they get something useful out of it like money or position. Whereas an otaku is obsessed for the sake of the obsession, even if that comes with some side benefits.