It makes sense. It's long enough after the initial poker boom to where players that stayed on have learned the game a bit and new players have different motivations than having a chance to go all in just like the guys they saw on TV. I hardly think this means anything too significant, as live poker will always be beatable, but it just won't be as profitable as it was a few years back, unless a new movie about poker comes out, or WSOP develops a new gimmick, etc. It's the same reason that a lot of online pros have turned to just playing heads-up; the competition has gotten harder and the playing field of gamblers has thinned out.