My feeling is that many GPs feel constantly under pressure to save money, so will not commission tests or refer to a consultant even when the need is clear.
DH presented his usual GP with the classic signs of Type 2 diabetes. He was also overweight and with high blood pressure, she dismissed his symptoms, which included extreme tiredness, as to be expected at his age (early 60s at the time) and still working.
We made an appointment with another GP, who listened to the same symptoms, said he considered them to need investigation, picked a small gadget off his desk and pricked DH's finger, showed him the result and said.' I think you have Type 2 diabetes'.
Difficulty diagnosing illnesses with varying and vague symptoms or rare problems, I understand. Dismissing patients who have classic symptoms of high incidence medical problems has no excuse and, from personal experience, this is happening far too often.