Like any arrogant SOB, at first I thought I'd come up with a unique solution to Euthyphro's dilemma. Turns out, I sort of have, but this is hardly rare. The trolley problem, Mary's room, Euthyphro, every philosopher has their own take on these things. I'm thinking I should collect all of mine into a diagnosis card, for the purpose of allowing rapid evaluations of me to be accurate. Find out the philosopher's intellectual lineage at a glance.
The strict logical answer is that gods like the pious because they're pious, as making them pious by liking them violates causation.
However, with actual liking in practice both come into play and feed into each other, as one can predict from general principle. It's weighted somewhat toward virtue, away from popularity.
If meter is good because people like it, then I suggest thinking about the generalized form of the following factor:
Things are sometimes liked because others like them. In this first fork, that makes the poem good. There is no such thing as a poem, that everyone likes, that sucks.
If people like meter because it is good, then they can fail to appreciate a good poem...but that poem is always appreciable.
This second fork implies that poems are good in ways that other things are not: poems are a unique form of wealth instead of yet another form of generalized wealth. Liking due to others liking it hardly stems from anything about poetry per se. Second, if the likeable trait is found also in, say, sand, it's probably not particularly poetic per se. Thus I can say that someone who likes bad poetry or music is not appreciating the art - I can only guess at what they're actually appreciating.
Moreover, no, in fact taste is not relative or subjective. Either poems offer unique wealth or they don't. Either a particular poem exemplifies that unique wealth or it doesn't. If they do and it does, and someone doesn't appreciate it, then they don't like and/or understand poetry, period.
Still, I do suspect this view uncharitably disparages the 'good because liked' view, and also makes untrue discriminations. I will think about it some more.
Using this framework, it becomes obvious that saying poetry is good because people like it violates locality.
I have a poem on Alpha Centauri. No one likes it. Then someone on Earth starts to like it. It instantly becomes good on Centauri. My evaluation goes from right to wrong but there's no possible way I could know.
If so, poems can be neither good, nor bad - rather a person's experience of the poem is good or bad. All you can say is some individuals like it, and perhaps predict based on similarity that other persons will like it. (The gods' experience of an individual is as pious or impious, and it is meaningless to claim that individuals are pious or impious.)
It has other problems with causation, too.
If it is predictable in principle when someone likes it, then it must be caused by the properties of the poem. If it isn't, then it violates causality. (Randomness does not solve this.) I believe this constitutes a reconstruction of a standard answer to Euthyphro: if the god changes their mind, but the individual doesn't change, for piousness to change means that piousness isn't a property of the individual.
More comprehensively, the prediction is based on the properties of the poem...and the rest of the observer's environment.
If there is any (unique-to-poems) contribution from the poem at all, then one can be mistaken about the poem and thus whether you like it, and thus whether it is good. And then taste is absolute.
At which point I suggest there are interesting implications for God. He can un-sin people by changing his mind. However, he's still bound by the laws of logic - he cannot make one person a sinner and another not due to the same action. This is very surprisingly restrictive because all the implications must also not contradict.
[Turns out Jesus isn't believed to be able to change the laws of logic.]
So I can just assume that it is impossible to make all free-willed agents non-sinners, no matter how the world is arranged.
Except...Jesus could use the null set, which has no contradictions. Now imagine what could make it impossible for Jesus to choose the null set.
A necessary antecedent: harm is bad by definition. The only question is whether harm can be said to meaningfully exist. I feel it's easy to show that it does: consciousness exists and doesn't like stuff. Anything which causes the not-liked stuff to happen matches the definition of 'harmful.'
I'm assuming Jesus can't use the null set, but if so, it can only be because the things not chosen would remain harmful. To be a sin and simultaneously not harm any consciousness is contradictory.
This means 'sin' reduces to 'unwise,' for Christians. Often just self-destructive, and definitively self-destructive for anyone who cares about not sinning against others. Which in turn implies morality is discoverable without God even if God exists. Even assuming the man is pious because God likes him implies that it's a property of the individual. The individual can then be investigated independently of religion. Which was Plato's point in the first place.
I believe those two lines of logic, about causality and about the null set, are independent, which means I've found a consistency. Which means it probably has integrity.