The Guardian summarises those invited and not invited to the NHS summit at Downing Street as follows:
Royal College of Physicians (London)
Royal College of Surgeons of England
Royal College of Obstetricians and Gynaecologists
Royal College of Paediatrics and Child Health
Royal College of Anaesthetists
Foundation Trust Network
British Medical Association
Royal College of General Practitioners
Royal College of Nursing
Royal College of Midwives
Royal College of Pathologists
Royal College of Radiologists
Royal College of Psychiatrists
Royal College of Opthamologists
Chartered Society of Physiotherapy
Faculty of Public Health
British Association of Occupational Therapists and College of
College of Emergency Medicine
There is an almost perfect split between this invited and not invited.
Those invited can profit from the extra private practice that can reasonably be presumed to result from the Tory changes, so are expected to support them due to their personal conflicts of interest.
Those not invited will not profit from those changes as many (but not all, I agree) enjoy little or no private practice. So they can be objective and as such see through the madness inherent in the proposals.
The split is just about as simple as that.