Are you kidding? AO and Wimby have best atmospfere from GrandSlams and it is even best watching experience on TV, FO and USO plays second fiddle.Tennis has never needed the AO, it always plays second fiddle to the US Open as far as hardcourts go.
Heck, Agassi didn't play the AO until 1995!
Plus why would you play 3 clay masters and then a hardcourt slam?
The French Open is forever, while the hardcourt slams are late on the scene and will probably be gone in the next 20 years as hardcourt injuries will not be acceptable when sanity prevails....
"Try to avoid playing on hard surface courts with no “give,” such as cement, asphalt, or synthetic courts."
--Atlantic Orthopaedic Specialists
Tennis Injuries & Prevention | Atlantic Orthopaedic Specialists
FO stadiums have extremely deppresed concrete grey look and like 10 people attend it even during last weekend.
USO has too big and wide arenas so tennis there is losing all intimacy and "feel"