FF14 is not the only Pay to Play MMO that has a cash shop. Unlike most other Free to Play MMOs, the cash shop isn't used to restrict your inventory, your ability to craft, your ability to access the maps at a reasonable price, it doesn't give you over-powered items or buffs, and it doesn't feel in any way, shape, or form like it's pay to win. It's Vanity, it's things you don't ever ever need and does not hinder you in any way, shape, or form.

Would it be nice if we could get some of these perks in-game? Sure! But you still get the dress and the hairstyles and the rings and the actual ceremony itself in-game. The money transaction only gives you more options and an extra mount/minion for loving the game enough to spend money on it so they can develop it even more.

There is absolutely nothing wrong with an extra paid plan for the Eternal Bond ceremony, because everything that is important to it is already in-game for free.