Trinity, speaking as someone who has worked in NHS IT, let me tell you they have been trying to update various systems to this effect for several years now.
However, the NHS does not use one homogenous system. At my Trust there were over 20 different IT systems in use, more when you included the community systems.
These systems aren't made in-house (usually). Therefore the NHS has to pay money to companies to update these systems, often at a cost of thousands each. Often there are limitations on how many changes can be made or how many fields can be included before the program gets too slow to run.
Some NHS systems still run on DOS. They are that antiquated. They don't allow someone listed as male to be added to a gynae clinic, or soneine listed as female to a prostate cancer clinic. The computers have only just been upgraded to Windows Vista. There is no money in NHS budgets to get new systems which would need to run on even newer computers.
So no, it's not "fucking useless" admins at all. There are whole teams of people trying to tackle this issue- I have been one of them.
The reason this has crept up on the NHS so quickly is because being transgender has really come to the fore only in the past few years. Several years ago if we received a complaint that a system had misgendered a patient we would write a generic apology but take no notice. Now we are bound by the equalities act and internal policy to make sure that all patients have equal access to services and that we do not create a barrier to that. Our Transgender policy was an absolute fucking nightmare to write and ratify, because no matter what we do we'll upset someone, so we're fucked whatever we do and it went through so many rewrites. There wasn't even an official NHS England Transgender polcy to base it on at the time! And we couldn't even begin to update the computer systems until the policy was written.