Totally agree with you, man!
First of all I'm not a follower of the "church of [insert here your character]" even tough I do have my preferences.
After playing BADIK a few more times, especially the interlude, I started to see Zoey's character from a different light. She made a mistake, motivated by the erroneous idea that the moment of her grandmother death, who always supported her (and from my own experience I connect with that part the story very easily) was her last chance to actually try a new life.
In her hasty calculation, made worse by the loss and consequent grief, she makes a decision that does not take the MC into consideration. And that's her sin. In my view, perhaps the only one, but it did a lot of damage to both her and the MC. It was playing again that I realized that I had made this mistake myself once. Friends of mine also, to a greater or lesser extent, made the same mistake. Who never? I really don't see reason for hate; I'd say, at least for me, it's more a question of broken a implicit confidence, a love that was generaly translated the only way rebel teenagers knows how: doing sex e stupid stuff.
And I agree: the moment couldn't be worst for reckoning between the two...and that's life!! Life doesn't give shit about the best moment for us to deal with bad choices, stupid ideas or dreams. The boomerang never forgets. Zoey and MC create another life for themselves when they both parted ways and to realocate what that person means to you, with all the fellings and memories...it's rather quite complicated.
Now, in terms narrative, to me it looked tha DPC just did it for sake of chaos, to add some spicy and weight to the choices tha may come yet
And sorry if I extended myself!!