Here's the thing, tall people have a bigger frame, and it's MUCH harder to fill up that space, it simply takes more meat to make a tall guy's proportions match up with a small guy's proportions. More muscle requires more calories to maintain, more calories means means his genetics have to be perfect to keep body fat down and off the gut. OR it means he's on drugs. Also tall guys have longer limbs, so a full range of motion requires them to lift the same weight a longer distance and more work (work=force **distance *). The distance also makes it harder on their joints. Essentially, taller=harder=more likely on roids.