I think a lot of people are having a go at the OP for the way he's phrased his post and are actually missing the point somewhat.
Yes, he's generalising and yes, he shouldn't be doing that but that is not his fundamental point. Not all doctors are incompetent and a majority will be very good at their jobs. However, one must acknowledge that there will be some doctors that display a large amount of negligence. The OP seems to have been treated by one of a minority of negligent doctors and a lot of you are attacking him, saying maybe it is he who is wrong, despite the fact that the GP would not give the correct diagnoses for 2 years, despite his persistence. The OP is then saying that these doctors who are incompetent and show negligence, should be held more accountable for their actions.
This is a perfectly reasonable thing to say. If a doctor is showing negligence, such as not referring patients when they should be, misdiagnosing etc then they should be held accountable for their actions and there should be an investigation into their practices to ensure that patients are being treated in an acceptable manner. If it is found not to be the case, then the doctor should be fired, as they are not correctly doing their job and patients are suffering as a result. This would only ever lead to higher standards of practice and a higher level of trust in our doctors.
Whether or not this would be feasible due to the large number of GPs, as well as needing to find replacements to those that are performing badly, remains to be seen. Perhaps so, perhaps not, but there should at least be an avenue to turn to when one wishes to complain about malpractice within the clinic. These are the topics which should be being discussed, not just blindly attacking the OP for having a bad experience and giving the doctors the benefit of the doubt. Now more than ever we should be questioning the quality of our health care in light of a number of very disturbing scandals, we shouldn't just blindly assume that all doctors will be doing the best job possible while assuming that the patient is in the wrong.