So if there really was an Achilles and Patroclus, which is likely - they may or may not have actually been lovers. But it would not have been uncommon at that time or among the inheritors of their culture and language.
Homer was as far removed from the actual persons (if they were indeed actual persons) as subsequent authors were from him. He may have either played up or played down their status as lovers according to his own proclivities or the reception he wished from his audience. The end result was one that certainly suggested they were a lot closer than just ‘brothers in arms’ - without outright saying they were lovers.
Subsequent writers, like Plato, interpreted Homer's work, and possibly works that didn't survive, to mean that they were definitely lovers.
What is clear to me is that it was not our own “over-sexualized” culture that interprets Achilles and Patroclus as lovers - and as such it was a horrid example.
It may well be a case, as you suggest, that the subsequent Greek ‘over-homosexualized’ culture interpreted these two semi-historic and somewhat mythological figures to be lovers.
But it is ABSOLUTELY CLEAR from the historic record that the homo interpretation is not a modern anachronism.
So far from being a good example of our “over-sexualized” culture emphasizing homosexuality - Achilles and Patroclus are actually contrary examples.
Their possible homosexuality, which was widely accepted in ancient Greece, was absolutely downplayed in our modern mass media culture. I think they saw the ticket sales for “Alexander” and decided their course was clear! ;)