To be fair most of the games have been on at 9am and 12 pm eastern time during the work week, but still, this tournament is invisible in the U.S.
The only international sports tournaments the U.S. cares about are the Summer Olympics, Winter Olympics, and FIFA World Cup. As the years pass, I believe the World Baseball Classic, FIBA Basketball World Cup, and World Cup of Hockey will rise in popularity as well, but non-best on best tournaments like the IIHF Ice Hockey World Championship, WBSC Premier12, and IFAF World Championship will never gain traction. Better chance of the Cricket or Rugby World Cups getting some buzz than a non-best on best tournament.
By the way, this is my source:
http://sportstvratings.com/.