It should have been an option if you play female, human Inquisitor. I can understand keeping out the non-humans and the male characters for the lore reasons. Being that the human Inquisitor comes from a family of faithful believers and can potentially be a hard core believer themselves, I don't see why not if you play a woman too.
The only thing I can think of is how upset warden players were when they couldn't rule Fereldan because they were a mage or dwarf or elf. The divine would be more limiting because playing male would be cut out. I imagine the MRA crowd would have been extremely upset about another blatant attempt at shoving the SJW agenda down their throats.