"Helen didn't even exist, why are you complaining"
Heathcliff didn't exist either, but that didn't stop people from complaining about him
Even then, there's a key difference between Heathcliff and Helen (same logic can be applied to Odysseus, Achilles, ALL of the Greek gods etc.) in the way their appearances are defined within their respective narratives, that everyone elects to ignore
In the case of Heathcliff, we have ambiguous features, such as his dark skin, that emphasize his status as an outsider, but we do not know his race or his ethnicity. The ambiguity of his origins is deliberate; it is used by Brontë as a literary tool.
In the case of Helen, we have no such ambiguity. She's a figure rooted in a specific mythology, in which her identity as a Greek woman is defined and stated. Her genealogy is made known to us, too. Furthermore, when Homer calls her "white-armed" (λευκώλενος), it's not merely a 'beauty ideal'; he's referencing what Greek women -what Greek people- look like.
The ambiguity of Heathcliff's origins is what allows him to shift in appearance across adaptations, so long as he remains visually an outsider to the rest of the characters and in accordance with his known features, because it's his 'outsider' status that is central to his story and his character.
But depicting Helen as anything other than Greek makes no sense, because her ethnicity is foundational to her myth. And her idealized beauty is not irrelevant to her ethnicity, it's tied to it.
So if you have a problem with Fennell's casting choices in Wuthering Heights, you should definitely have a problem with Nolan's casting choices in the Odyssey.
You bunch of hypocrites :)
