Why?((( Because phpBB is one of the main CMS. And many switched from phpbb 3.0 to phpBB 3.1. A lot of people looking for ways to migrate to Xenforo with phpBB 3.1. The only way it is, it is in myBB first and then to Xenforo. But this method is very, very comfortable! On the forums with lots of messages, this method does not exit.
Because for You it will not be easy. And good for you. Please respond! Please import from phpBB 3.1....((((