Fruit doesn't fill you up. If you read about fructose and the way it overrides your appetite, you will see why. When I quit sw and went low carb/high fat/sugar free it was a revelation as to how sw isn't really the dream diet I once believed it was. There really is no benefit to bring able to/allowed to eat unlimited quantities of any food, but high sugar foods especially. On some days at sw I would eat circa 500 calories of fruit, and all speed food and all 'allowed'.
I will point out, I am not smugly polishing my halo when I say this. I am a long suffering yoyo dieter and I'm not perfect and fully understand why different people do different diets. The sw extra easy sp plan is closest to the best diet for me really. Actually, the old red plan, but that's 'that which shall not be named' in classes now. But substitute full fat for low fat dairy. So, free protein, 2 b choices (but have nuts, oats or lentils not bread!), 1 a choice, watery veg. A small treat each day. Have full fat yoghurt once a day or every couple of days as a dessert or breakfast. This is the basic premise of many popular diets at the moment, such as the blood sugar diet which I am currently doing.
The problem with sw I have found is that due to this mentality of 'you can eat loads of food' it can attract a certain type of dieter who believes that they cannot cope without loads of food. It encourages this 'how much can I get for my syns' mentality which results in delights such as scan bran cake, pink and white marshmallows, all manner of concoctions made out of muller lights- even sw themselves have come out and said that if you use free food in this way then you have to count it as syns. Not every member, but lots of them. When you read threads on here, a large amount of successful sw weight-losers are those who don't eat all the zero Syn foods, but instead cook wholesome food from scratch and exercise portion control.