I get the miracle of science thing all the time
My back and chest got a lot bigger as did my quads and hamstrings. I looked silly, big chest and back and skinny arms. I'm a bit more in proportion now, but I train my chest and back with a lower volume than I used to and my arms with a higher volume.
It would not defy science to have a muscle atrophy from training it less. I have large lats for my frame, I used to get asked if I was a swimmer when I was smaller. My lats tend to do the work when I do back exercises, what a surprise.
You can sit at home with your facts all you want. I don't care, I'll do curls and have muscular arms (btw they suck right now due to this kind of bullshit, I used to get complements on my arms. I will curl even harder knowing you disagree with me).