It's also one of the oldest. There was a time when nearly all competitive golf was played at match play. Even today, most of the weekend club golf played around the world is some form of match play. It's obviously the masses' preferred format. Sure, there is the added element of nationalism, but some of the interest is clearly generated by its mano a mano format.
Match play is just more compelling.
Sure it would restore the PGA's point of difference, but it's also a helluva lot of fun to watch and to play. The beauty of match play is that you see blood immediately and you see it on nearly every hole. Somebody wins and somebody loses. When the Bulls and Pacers play in the NBA playoffs, we get a decision. We get some satisfaction, some blood.