As I see it, it has two uses.
1st - forum about medicines and operations etc - trading on the name "NHS" will get you shut down
2nd - forum about experiences of the NHS - would probably be a legit use of this site but the market for a forum about the NHS must be so small.
Who has much to say about the NHS? Very few people IMHO, maybe old people (who don't use forums anyway) and people who want to complain about how slow it is to get an operation etc.
I don't see much of a target market for people who want to talk about the NHS. Even if it could succeed, it'll just be full of complaints.
Every post would be the same - "this was slow" or "I've been waiting for ..... months"
Value? Maybe a little over reg fee, nothing more.