In his initial letter, DR acknowledged that Jk Rowling was “unquestionably responsible for the course [his] life has taken“ so he disagrees with you. Harry Potter movies were not successful because of Daniel Radcliffe. I don’t think it can credibly be said that a different HP actor would have led to less success. He isn’t even very good in them. Taking DR out of the movies doesn’t affect them, taking JKR’s creativity in writing books in the first place very much does. So this: If you go down that road then I could argue that DR is responsible for JKR earning millions from the HP film series because he brought legions of new fans to the series but I won't is nonsense.
In terms of his opinion, he is entitled to it, and if he had simply aired an opinion saying he believes TWAW then that would be one thing - but he didn’t. He went rather further.
He publicly called her out, personally, for “erasing the identity and dignity of transgender people”.
he went on to apologise on her behalf to anyone who has read the books and been upset by the comments:
“To all the people who now feel that their experience of the books has been tarnished or diminished, I am deeply sorry for the pain these comments have caused you. I really hope that you don’t entirely lose what was valuable in these stories to you. If these books taught you that love is the strongest force in the universe, capable of overcoming anything; if they taught you that strength is found in diversity, and that dogmatic ideas of pureness lead to the oppression of vulnerable groups; if you believe that a particular character is trans, nonbinary, or gender fluid, or that they are gay or bisexual; if you found anything in these stories that resonated with you and helped you at any time in your life — then that is between you and the book that you read, and it is sacred. And in my opinion nobody can touch that. It means to you what it means to you and I hope that these comments will not taint that too much”
he hopes her comments will not taint people’s love of her books too much? What possible right does he have to comment on the books like that?
That goes way beyond just stating his opinion, he is knifing her. He all but calls her a bigot. She has continued to state her opinion but hasn’t (as far as I know) said anything about DR or EW. And yes, only one of them is getting death threats - which i don’t believe DR has troubled himself to condemn?