I recall that somewhere Flannery O'Connor complained about the condescending letter she received from her publisher, and I would like the exact reference / quote. The complaint was something along the lines of 'it used terms that one uses in addressing a child'.
Sally Fitzgerald, in 1979, published a massive volume of Flannery O'Connor's letters titled The Habit of Being.
According to Fitzgerald's book, in 1948, O'Connor began an exchange of letters with Elizabeth McKee. During this exchange, in late 1948 and early 1949 they discussed shopping O'Connor's novel chapters around to various publishers. O'Connor mentioned that John Selby, editor-in-chief at Rinehart (publishers), wanted to see the first nine chapters before he would write up a contract. After he received the chapters, he wrote to O'Connor a letter that is not preserved in this book. However, O'Connor's letter to McKee discussing Selby's letter is printed in full in the book. An excerpt is below.
February 17, 1949
I received Selby's letter today. . . .
The criticism is vague and really tells me nothing except that they don't like it. I feel the objections they raise are connected with its virtues, and the thought of working with them specifically to correct these lacks they mention is repulsive to me. The letter is addressed to a slightly dimwitted Camp Fire Girl, and I cannot look with composure on getting a lifetime of others like them.
Camp Fire Girls (now Camp Fire) was started in 1910 to give girls outdoor experiences; it went co-ed in 1975. A Camp Fire Girl would therefore be a child of between 6 and 17.