So here is my take on the whole genetics issue:
Everyone has a predefined genetic potential that they can reach in bodybuilding, sports, musical instrument playing, etc. How close you come to your own genetic potential depends on how hard you work at it.
However, there seems to be some people on here who think the complete opposite of what I posted - that everyone is created equally, and hard work conquers all. If you aren't as big or as strong as person X, then it's only because you don't know their routine, and/or you don't work as hard as they do. If you mimic their routine and don't get their results, you must not have been trying hard enough.
What are your thoughts on this?