I think it's true, we do expect too much from our GP's, but usually because they are our foot-in-the-door into the world that is NHS. Not being listened to by a GP is frustrating, and can make someone feel like they have to deal with their health issues on their own. I was a carer for my grandmother, who initially had long term mental health issues. About 12 months ago her physical health deteriorated suddenly - within days she went from walking 2 or 3 miles a day to being unable to walk to the bathroom unaided, but it was extremely difficult to get a GP to listen. We were fobbed off with "normal age-related deterioration". Eventually, after I fought with everyone at the surgery, she was referred for further tests. Within 6 months she had died of pulmonary fibrosis (a condition where lung tissue loses it's elasticity, making it difficult to breathe and the lungs fill with fluid). The condition couldn't have been prevented, but had someone listened from the start, it could have been managed better, she would have had more time, and her death would have been more comfortable.
The very least we should expect is that our GP's listen to us and take us seriously. In my opinion, that is the very minimum expectation, but many aren't even meeting that.