Haha, well...
1) The color of his sox.
2) Im a bitter Braves fan that thinks Murph is just as deserving and didnt get close. (if not more deserving based on my team bias...)
3) He was a little too close to the early steroid era, and I wouldnt vote for anyone thats is related to that time, even by distant associations.
4) 3) is obviously not serious.
But my main thought is that there has to be a cut off at some point for induction. Its obvious that he was at the lower end of the spectrum according to the voters over the last 15 years, and I would much rather have the cut off be too high than too low. (The Murph the exemption. lol.)