PA-PLAYA Over the course of 72 holes, it just seems more reasonable to me that the more talented players finish in the money that week, versus 54 holes. It could also be argued that the cut line is also a form of a tournament, adding its own element of pressure.
Why not make them 90 holes then? The only reason 72 holes seems important is because that's the way it's always been. Just like whoever decided 18 holes was a "round"