They were probably going to lock weddings behind a gil wall anyway if it weren't for the cash shop. By making the plan tradable anyone has enough access to wedding of their choice. So basically the new wedding plan can be treated similarily to new glamours pay "X" amount of gil to player to acquire that glamour if you don't have the capabilities of a master crafter. Also this allows players to set a market for how much they want to pay for these plans so could be relatively affordable depending on the economic situations. Even it isn't it gives you and your spouse something to grind toward to make it seem liked you earned having that platinum wedding. As long as people sell these plans in game, eternal bonding is accessible to all so there really isn't much reason to complain about it.