"I think the more we can all, despite our huge numbers of various beliefs, can simply agree that life is incredible and short and therefore we need to spend more time caring about each other and appreciating things more would seem to do the species better than simply trying to show how stupid someone else is because they have a different belief system than we do."

While I can agree with much of this, the problem is that many belief systems do not allow for this. Particulalry the religous variety which tell you to go and and convert (and in some cases kill) anyone who doesn't "believe. This is what I think Hitch has a problem with.