writing academic english
Hans Reichelt, in the Preface of his Avesta Reader: texts, notes, glossary and index, Strassburg 1911:
Finally I beg the reader not to criticize my English two severely. I have only written the book in English because I was specially requested to do so by the Parsees who do not understand German.”
[update!] The above reason for writing a book on something relating to Zoroastrianism in English is apparently common. Thus Henrik Nyberg in his Manual of Pahlavi, Wiesbaden 1964:
If I send forth this new edition of the Hilfsbuch [his 1928 German grammar of Pahlavi] in English, it is solely in order to facilitate the use of it to our Zoroastrian friends in India, who, as a rule, do not understand any other European language. I apologize to British readers for a foreigner’s English.