Not all teshuvos are from submitted shailos, but let’s say a person wrote a shailah to a rov asking what the best ice cream is; does he have to answer it? What if he asked “is it allowed to kill my neighbor when I’m mad at him”? There are some questions that are illegitimate. Choosing to write answers and publish them means that you take the question seriously. Henkin “grappled’ with this question, because a tzadik, a kadosh vetahor who survived the concentration camps and learned and taught more torah than henkin with his tiny yarmulke followers can ever imagine. He also literally built up half of of klal yisroel when henkin was a child.
Comparing the satmar rov with henkin is like comparing me in 8th grade biology to jonas salk. that itself is insulting. It sounds like much of your jewish education came from online forums; in the yeshiva world, henkin’s name is not even known. In the dati leumi world, henkin was a posek, but even they acknowledge the greatness of the satmar rov as a giant among giants, and would not compare the two.
As for rabbi kook; some do not want to write zatzal because of the damage he caused, leading to the henkins, riskins, lamms, stavs, and melameds of the world, which undermine torah and mesorah.