Come to think of it, if "trees grow roots most strongly when wind blows through them" because the trees with weak roots can't survive in those conditions then this would make a very bad metaphor for people.

No, it's probably accurate as stated. I don't know about trees as such, but if you try to start vegetable seedlings indoors and then transfer them outside, they'll often die in the first major wind; the solution is to get the air around them moving while they're still indoors (as with a fan), which causes them to devote resources to growing stronger root systems and stems.