Because this tournament is a complete joke. That's why few top teams (from anywhere) attend it.
Well you do have to win a qualifying tournament to attend, so there are some very good teams here. There are also some weak teams. To get to the final four the teams are very good for the most part. It is well run and fun, what you want in a tournament. And spending a few days in warm weather doesn't hurt either. And there are several top teams here battling it out today, no joke!