Read all posts in Mahmud Rahman’s investigation here.
An unfortunate reality is that there are not enough good translators working in South Asian languages. There are some in the subcontinent and elsewhere; but in the U.S.—presumably where it is most likely that translators might approach U.S.-based publishers—there are only a handful. If you look at the directories at ALTA, PEN, or Words Without Borders, these languages barely register. You will find a few working in Hindi, Urdu, and Bengali, but hardly any in Tamil, Malayalam, Punjabi, Telegu, Nepali, Sinhala, or other languages.
The emergence of translators here is also largely a matter of chance.