Why cannot both be true? You write something for yourself, but also publish it in the event that it benefits someone else. But even so, I think the context her

Why cannot both be true? You write something for yourself, but also publish it in the event that it benefits someone else. But even so, I think the context here was more like "write the sort of book you would like to read", not strictly "write the book so that I and I alone can then read it".