Why are children who are in 3rd grade in booster seats?

OK I had a co-worker who had two children. Two little girls, one five, the other eight. I think at six and eight, they are little kids, but definitely not a toddler or a baby. Why is it at lunch I went to her car and saw two car seats in the car. At first I thought maybe they are both physically challenged. They ain't, those children can run and move, I met them, they are sweet as can be and very much the "normal" children we expect. I finally asked her why she has car seats for her kids. I remember me at five going to school without a seat belt in the back of a stationwagon. Safe. She finally told me experts believe children should be in booster seats until they are four feet, nine inches, up to eighty pounds!!!!!!! Hell that knocks out all midgets, and dammit if they child can do division, they are really too old for a car seat. If you can put yourself in the booster seat, you are probably too old for it. Honestly, how did all us kids survive in the back seat just using an adult seat belt. Imagine the embarrassment these children face. All the other kids are taking themselves to school via walking, bike riding, rollerblading, and your mommy is driving up with you in a damn car seat. What the hell, you are going to get picked on all the way to high school. You never had a chance.