You may have wondered, as you read it: did Rabbi Moshe Feinstein himself ever (get to) see it?
Of course, he had his detractors. There was a sefer that was published by Satmar entitled Ma’aneh la-Iggeros which tried to take apart over 160 of my shver’s teshuvos. But he was so immune to personal attacks. His perspective was: I publish, they publish, you read and decide who is right. Attacks did not bother him. In addition, Satmar’s Ha-Ma’or attacked him regularly, but he would never respond. Only if you wrote to him or called him up with a shayle would he respond. The one time I ever saw him reply to something someone published about his stance on an issue was when Ha-Ma’or criticized his take on the question of artificial insemination and whether the child was considered a mamzer (illegitimate child) or not. He felt that he needed to defend his position publicly and in print, so he responded in the back of the Dibberos Moshe on Kesubbos, which was being printed at the time, with three teshuvos devastating them and showing their amaratsus (ignorance).