I don't play baseball, but I like to think I have some semblance of physics. If he has more bodyweight, then doesn't he have more to put into the ball?
Anyhow, although I don't like people making that point, the only reason people talk about throwing the asterisk is because people are jealous. They're jealous they don't have the work ethic to be as good as Bonds. They're jealous that Bonds is able to do whatever the f*ck he wants, even be an arrogant a-hole and the people still cheer for him.
Heck I'm jealous at the money he's making off playing a game he probably dreamed of doing as a kid. At least I can admit it.
People like to knock people who are in high places. Everyone wants to put the asterisk there because it makes them feel like "Oh well I could do that too if I chose to take illegal drugs."