It does address the issue of adopted children - we as a culture have a fixed mindset for things like introversion and intelligence, and genetics do strongly influence our default level of both of those. Thus, adoptive parents observe the child and say "you're an introvert" or "you're not clever" and the default pattern is reinforced.

On the other hand, when a child displays an initial dislike for like Taylor Swift, her friends might say "you're crazy, Taylor Swift is awesome."

It's all just neural networks being reinforced or inhibited, the primary contribution of genetics is the default state of the network. In the case "fixed" personality characteristics, our culture is to reinforce the default networks, while for things we view as mutable, we have no qualms about training away default behavior.