I am sure there should be no worry attached to children having a healthy snack after school if they still eat their evening meal.
But we are definitely in a diabetes/obesity crisis and the NHS are performing around 100 amputations each week. That is around 5,000 per year!! 
Small children still have a healthy insulin response, and are very active, but even slender adults can develop diabetes, and sweet treats are not going to help avoid this.
As to rice cakes, yes, we were sold these as a healthy option, but the truth is they are so refined they are digested too quickly, and will cause a sudden sugar spike, especially the caramel coated ones.
My personal problem is that the perceived wisdon, handed down in the last 40 years, of low fat, frequent grazing/snacking e.g dried fruit as part of my daily 5, has led to overweight.
I have worked out I was consuming about 1Kg of sugar per week in foods, e.g. healthy fruit yogurts, which was costing me something around £10 per week. I might add that I haven't bought a bag of granulated in more than 20 years.
From extensive reading I now understand that every time I put anything in my mouth an insulin response is created, and it seems to me my only answer now is to cut out all processed foods containing more than 4% sugar. A bit harsh, yes, but I have lost 1 stone in the past 2 months, and a glucose test on Friday gave 4.3. So perhaps at last I am winning the losing game!