I agree totally.
The movie is essentially a total rewrite that uses nothing more than the poem's title and character names. Few other details, motives, lessons, or tensions were retained. It should have been called The Odyssey: A Parody.
It is worth mentioning that the original poem was never intended as a strict historical account. One can retell history through a few different lenses: from the perspective of a neutral investigator, from a cultural perspective, or through the literature inspired by that history. The Odyssey was a mythic epic in that third style.
Homer's original poem was written down after many generations of oral tradition in Greek culture around 3,000 years ago. That it survived is a testament to the cultural value of the details, motives, lessons, and tensions embedded within The Odyssey. None of those values made it into the movie.
The issue is not simply the (laughable) liberties taken with casting or the historical inaccuracies. The movie deviated so far from Homer’s vision of a heroic, faithful, and tragic King of Ithaca that calling it The Odyssey is fundamentally dishonest.
Homer’s Odysseus feared and fought gods and mythological creatures while longing for home (nostos, the word where "nostalgia" is rooted). He was confident and clever (metis) and didn’t waste words.
By contrast, Nolan’s Odysseus is a war-haunted loser whose deep trauma and guilt manifest as a brooding, obsessive narcissism focused on securing his throne, people, and his woman.
This movie may indeed be a hit at the theaters, but it is not The Odyssey. It is a parody.