why does he do this, and why is it so intersting?

I always thought that "Alexander Supertramp" (Chris) was a bit of a jerk. Some justify his behaviour as being a free spirit. They feel that he was breaking down the barriers of a conformist materialistic society. Chris was experiencing life deliberately instead of buying into the illusion that the rest of the world lives in. There is, to be fair, some truth to this. Chris, however, forgot that we are here for our loved ones. There is a certain amount of respect one gives to their family regardless of any personal revelation or quest. Chris seemed to feel that these strangers he met shared and were a part of his new life. Unfortunately his family would wait in worry until they found out the news of Chris's lonely and painful demise.