The main point of Chirac's non-attendance is that he missed an opportunity to change American opinion about the French. Contrary to what Kerry has said, among other more out of control liberals (Dean and Gore come to mind), Bush has not done anything or said anything to purposefully alienate the countries of Europe. He has not used inflamatory rhetoric or US power against either the French in general or Chirac in particular. Indeed, President Bush has gone out of his way to make it clear that while he was disappointed by the lack of support from France, Germany, and Russia in dealing with Iraq, he still considered those countries as friends and allies. The American people, on the other hand, have made it clear that they considered the policies of France (and to a lessor extent, Germany and Russia) as a betrayal by a country we thought we could trust.
Chirac could have taken this opportunity to try to heal that rift between our countries (something the US Administration has been trying to do since the Iraq invasion) by showing Americans that he does not see us as a potential foe. Rather, that our two countries stood side by side (even after France's withdrawal from NATO's military alliance) during Reagan's watch to oppose the evil of communism. He showed himself to be far more inept as a statesman than either Reagan or President Bush.