Yes that's right. Glinner entered into this arena, and stayed in it, to boost his profile and career. That's the obvious conclusion that makes total sense and is completely plausible.
Its certainly more plausible than the alternative explanation that Glinner is a man who lost everything to stand up for a group of people he is not even a member of, and lost his friends, his acquaintances and his career, and saw everyone ostracise him and this has gone on for years, leaving him in an ongoing traumatic situation and it really, really would have helped to alleviate his self of vulnerability and isolation and psychological distress if a high profile figure had spoken out in his favour. The silence instead compounded the feeling of isolation and social shame and shunning. I am not making an argument for what JKR should or should not have done. I am saying I do understand how Glinner experienced it the way he did, and its reasonable for him to have felt that in the traumatic situation he was in. Being shamed and ostracised and unemployable like that is traumatising.g
You may not have experienced this type of situation, but I have been through a long term situation very similar to Glinner's and a completely understand where he is coming from on this.
I think the man is an absolute hero who has lost everything to battle for women and girls. I admire him.