FFXIV - Buried Memory (Poster)

[Enkidoh]

And yet we still have to use an eorzean deity in our character sheet in the creation menu instead of anything having to do with our race make it make sense

Because your race has no connection to your chosen deity (really the only race that has any specific connection to one of the Twelve are the miqo'te, with the Sunseekers devoted to Azeyma and the Moonkeepers to Menphina respectively - Guardian deity is more connected to a city rather than a racial group in Eorzea, but you are under absolutely no obligation to choose that one specifically, which one you choose is up to you),.

You take a member of the Twelve as your guardian because it's considered a cultural thing to do so for travellers upon arriving in Eorzea, "when in Rome do as the Romans do" and all that, and especially so when joining up as an adventurer.

Chosen guardian no longer has any connection to gameplay anyway so if you dislike it that much just ignore it on the character sheet.