My theory is:
Pre 2015 Stonewall was a respected organisation with a mission to continue to promote social acceptance of LGBs, often via training and help drafting policies. There was a revolving door for senior staff between the organisation and its clients. The approach was soft and safe, indeed on the question of gay marriage, very safe. However also effective, with lots of evidence pointing to the younger generation being more accepting of homosexuality than their parents. However there was still sensitive and careful work to be done, not least with socially conservative communities for whom understanding and acceptance of British norms is a key part to their own integration and equality. .
At the same time the Ts were lobbying to be brought into the umbrella. My best guess is that the decision was made before appointing Hunt, and adding the T was the first question at interview and the first task on appointment.
Why? At that time there was an awful lot of Kool Aid floating around, particularly from the US: Caitlyn Jenner etc. Even those who had their doubts may have worried that they were simply repeating societal concerns about gays of a couple decades before. Acceptance without exception sounded right.
What went wrong?
Stonewall, structurally, was ill equipped to consider new, and controversial policy issues. In 2015 it was what it was, and did what it did, with little transparency or controversy. My guess is that neither Hunt nor the Chair really understood the implications of adding a campaign that did not have wider public acceptance and which created conflict with other groups in society. Neither had the background, skills or experience to negotiate treacherous waters whilst keeping their core supporters on board.
The next error perhaps was their trans-advisory committee. It is hard to work out how this group fits into the Stonewall decision making, but they might have been better off including some people who appreciated the concerns of other groups in society and the need for negotiation. And the CE/Board should have been able to provide further Governance/brakes/dilution to ensure they were not moving too fast for Stonewall members, clients or society. Having a young and inexperienced Aimee Challenor on the Committee was poor. Having anonymous members is shocking.
Then there were the tactics. No one but no one should be demanding "concessions" (including safeguarding protections) from other groups using a shouty #nodebate approach. If societal change is needed, debate it, and provide your justification. And listen to the concerns of others and work out appropriate safeguards.
The inevitable push back has started to take place. Respected gays, like Jonny Best and lesbians are speaking up. Respected journalists like Janice Turner and James Kirkup are speaking up. Respected donors are speaking up. Respected medics, scientists and academics are speaking up. There have been some good, questioning, programmes on TV and radio. And ordinary people on Twitter, Fb, or Mumsnet.
Stonewall has remained, well a stonewall. However I am sure the pushback has started to affect their client base. More employees are now prepared to write to their personnel department, attaching an article from the Sunday Times and questioning whether Mermaids/Stonewall etc training is suitable. At minimum some will be asking why all the emphasis on the T, when managers really want to know how best to support the, say, sheltered but bright Bangladeshi girl in their team, or the person with disabilities. Teachers and GPs too. I also have no doubt that the pre-GRA advert linking to the Stonewall guidance, and using the logos of 40 firms, did real harm.
So did Hunt walk, or was she pushed? It really does not matter. She did not understand the task and did not have the skills, so failed.
What does Stonewall do next? If they are sensible they hire a savvy politician. A Mandelson type, who can understand the task, sort out sensible targets and rein in the less-compromising TRAs. They slow down, rebuild the respectability of both Stonewall and the transgender movement. (Note very few people had issues with the GRA and those with certificates, and the prevailing view is one of sympathy.)
They acknowledge the big concerns: medicating children and the unwell; sport; and safeguarding, and offer compromises. They seek smaller and sensible reforms to the GRA, not Self-ID for the full umbrella, review the guidance they provide to people like schools and the police, distance themselves from the more fetishistic elements, and start encouraging debate.
Will they? No. I don't think they can. I don't know who was pulling the Stonewall strings but suspect it was neither Hunt nor Gooding. Both were simply there as beards, to be pushed when no longer useful. .