Why are there so few good restaurants

If I go to a doctor I expect that he is qualified to examine me, and like wise a dentist. If I take my car to a car mechanic then the same applies, it is that he is qualified to repair my car......YET.....if I go to a restaurant then anybody can present me with a meal. The quality of food that is served in Cape Town is shocking. Cafe del Mar in Camps Bay overpriced and unable to serve a decent basic salad. Extreme Hotel...millions spent on the decor.....yet they specialize in undersized average hamburgers.....and if you want any extra condiments you must pay.....Cafe Paraidiso.....oh so average.........Manna.........there is nothing on the menu, it is a joke.........Jimmys Killer Prawns....give me a break....the list goes on and on