I can't speak to the parent's tone, but having worked with excellent designers who can and cannot code, I have often found that those who have made the choice t

I can't speak to the parent's tone, but having worked with excellent designers who can and cannot code, I have often found that those who have made the choice to learn to code, even just a little, produce a better outcome. You see the same thing on the flip side of the coin with frontend engineers who make the effort to learn about typography, color, emotion, etc. Broader skillsets produce better software. Related - moving a button 3px to the left shouldn't be a problem for any self-respecting designer, either.