A friend asked me that question this weekend. There are, of course, plenty of answers to that, but this screen shot showing the location of recent visitors to this blog helps explain part of the appeal I think:
Hello World! The last 25 visitors alone have come from: the UK, the USA, Canada, Pakistan, South Africa, Poland, Belgium and Germany. Obviously there's a certain egotism to this sort of exercise, but it's also kinda cool to think that, for whatever reason, folk from all manner of different countries and of all kinds of different persuasions can stumble into the same tiny corner of the blogosphere.
[Hat-tip: Englishman in New York who once, I think, answered this question the same way.]