John Horgan writes that he thinks physicists are drawn to the multiverse idea (which he dislikes) because they cannot bear to think that our universe will end at some point. He postulates an explanation for why multiverse theories are so popular among physicists despite the lack of any supporting evidence for them.
Here is my guess: physicists are freaked out by the mortality of our little universe. What was born must die, and according to the big bang theory, our cosmos was born 14 billion years ago, and it will die at some unspecified time in the far future. The multiverse, like God, is eternal. It had no beginning; it will have no end.