The PHRF rule is exactly what the letters stand for. This is a simple rule which is designed to provide a handicap for a particular type of yacht for a particular area. It does not favor any specific type of yacht.
Some owners prefer exciting boats.
Stiff, light and lots of sail will produce this type of yacht. Others prefer a real cruising yacht, heavier, lower righting moment and full of cruising gear. One yachts handicap may be different in different areas. This is because these boats perform differently in different conditions. There is no rule nor has there ever been one nor will there ever be one that can take into account different yachts performances unless each yacht has a specific handicap for every different condition and point of sail.