Don't be too crushed, training your legs hardcore will definitely help your upper body grow. Squats, heavy ones, have proven to help release GH thereby causing overall growth. My upper body didn't start growing fiercely until I started squatting with multiple 1 reppers. One friend of mine did nothing but squats for three weeks straight and he gained almost a 1/2 inch on his arms and an inch on his chest. Trust me it works!