Primary health organisations and their general practices are paid according to the number of people enrolled - not the number of times they see them.
"Human behaviour predictably will be to enrol as many people as possible who will never come in and see you, and to make yourself unavailable.
I presume the idea was that you get base funding for the number enrolled, then charge a fee to cover appointments. But they have a point, it comes across as a bit WTF in the current environment.