Fixed Menus ...Many Courses ...augh

Pet hate at the moment: restaurants with fixed menus ... I thought that was the thing you got in a bad restaurant in Paris : the dreaded Menu Touristique (usually written in English or German).

I like to eat what I choose, not what the chef decides.  I also sometimes like to pop in and have a "light" meal in a great restaurant.  So why do some of these establishments only offer fixed 3 or 4 course menus (or even more!) ????
Paramount, Christine Mansfield's old restaurant in Potts Point had hats galore and was happy to let you in at 9pm and and have a main and a glass of wine. Quay is one of the pompous "menu fixee" places  ..either 4 or 8 courses there ...augh !!! Too much food for me and not the combination I want.