Maybe you guys haven't noticed, but most nba players have skinny legs. Even Bonzi who we all know is fat has skinny legs. Lets not blame the legs now.
This is why professional athletes hire full time personal trainers. The very first thing a trainer does is learn his clients body type, it's metabolism, etc. In case you haven't heard Tracy was born with a small curvature on the back, scoliosis. This is why many only thought his career would last at the max five years. His workout regiment is taylor made for his particular body. By the way, it's not squats that keeps an athlete athletic...if you are an athlete which needs to get airborne, without having to crouch down, before going up, the last thing you want are huge legs, calfs, etc. You need quick twitch reflexes. Remember Stevie Franchise when he first joined the league? The man could lift off out of the gym without effort. Have you ever noticed the body type differences between a tiger and say a rhino? Tigers are long and lean. Rhinos are strong and huge. Who do you think are the best jumpers?