The NHS is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to the NHS.
It's also not one thing, "The NHS" is a bag of marbles under one title, all with different legal statuses, managment structures, budgets, aims etc.
Bringing that into some form of coherance will take time as well as money and as mentioned by others if politicians like to come in and shake it up up every 4yr or so the job will never happen.
My first interaction with NHS IT about 20yr ago was a bit fightening as the team had no concept of server hardening, patching or any maintenance, it wasn't a refusal to do it, they really has no concept of it at all. Vanilla out the box and left was what they did. Years later further interactions showed a vast improvement and they worked well with the local authorities around them as well.
NHS Trusts are a bit like schools in that the management largely comes from the ranks, which means they often come with a closed mentality. Security guys don't help themselves or the organisations by often adoping risks and responsibilities they shouldn't so as not to bother the board. Risk and governance are your friends in this circumstance.
Following their own defined processes, you have to play the game. THEY own the risks and raising of the risks to the appropriate forum is how you start the process of education the board of their responsibilties. If they don't like to follow their own governance then you document and you record and you cover your arse.
Infosec is 90% psychology and 10% technology.