You don't need materia melds to clear raids tho. With enough gear you can do a fair bit of progression but you won't be pushing the last floor on the first week.
In the end BiS melds are just for speedkills and world firsts and bests.
And stats weights and BiS for every class are posted by the players that do the theorycrafting themselves. Those you unfairly label elitists because you don't know the stat weights that were everywhere around 3.0 and will be everywhere around 4.0 once they figure it all out.