This is not incorrect, a tree's mass does come partially from the soil, it's just that the majority comes from the atmosphere. It's not like the tree just puts out roots cause it likes the feeling. Where do you think all the water mass in a tree comes from?

I would more chalk this up to too little biology, too late, for people to learn well. And, frankly, it's not something everyone NEEDS to know; misunderstandings are not the end of the world.