Since children and adolescents have ample study time at primary level and secondary level, this time should be limited to studies and not spent on other activities.
I agree that children should only focus on studying as much as they can however I think letting them know about bitcoin gives them another opportunity or another path of career. They might figure out later on that they might be interested in finance or in technology.
Let’s also not forget that not all children are able to finish their studies. By giving them a chance to learn about bitcoin, they can learn how to invest and finally make a living of their own.