Kids from a very young age are given snuggly manmade fiber blankets. Personally, I'm not a fan - but it's what they are exposed to and they quickly become a favorite. Think minky or fleece.
Quilts are also harder to care for. Those same blankets mentioned above go into the washer and dryer, no special handling required. They aren't as bulky and dry quickly.
I love the weight of quilts with cotton batting, and only use natural fibers - but that is not what most younger people want. I like Sewingitalltogether and WesternWilson's suggestions.