A relatively minor point in the context of this discussion, but a number of charities will lose out as a result of the intransigence of many transactivists.
As I said upthread, I have cancelled my subscription to Amnesty (after decades of support) and have also removed my support for Stonewall via the Amazon charity thing. These are just two organisations, but I am sure there will be many others who feel obliged to make a policy on the topic but find that it loses them support in the end.
Retail has run into problems by insisting that men who identify as female can use women's changing rooms (terrifying for many women who have been raped), there are instances in the NHS of women being treated by male staff who identify as female (same applies). Prisons are public institutions, and ones where very vulnerable people are housed. To allow men who identify as women to be treated as female is risky at best, surely?
In all of this, however, is the fact that transwomen who have fully transitioned are caught up in the arguments about men who self-id being allowed to call themselves female. IMO there is a huge difference between someone who has genuinely committed to being a woman, with all that this entails by way of hormones and surgery, and someone who still has a penis but wants to be considered female.
This is why there needs to be a debate, and why it is so frustrating for those who want to be supportive of people like growstuff's friends who just want to live their lives in their own way. We are told that we can't be supportive unless we accept that being female is about wearing a dress and using a female loo, and that we should move aside to allow men to join us in places that we have struggled to make safe from them.