I guess for me it boils down to this: it makes no sense that an admittedly entertaining story could give birth to Arthurian legend, as plainly stated in the movie, if it has next-to-nothing to do with Arthurian legend if not lip service.

Some details, admittedly, are put in with finesse - the sword in the stone, Lancelot's yearning for Guinevere. But, if there is no succession problem, no illegitimate birth, no pagan priests and priestesses fighting for the survival of their religion (all things perfectly believable in that time, if you take away the most "magical" aspects), how did so much of it get into the legends? If you put in a fighting Guinevere that left no trace in the legends, what on earth is the connection between "King Arthur" and the legends it claims to have inspired? Fighting for freedom, yes, but there are any numbers of ways to do it.

Some will raise the objection that a warrior Guinevere would be anathema for later Christian writers and so they erased her. But how come there is no trace of her even in Chrétien de Troyes, the most feminist and enlightened of the Arthurian writers, who goes well beyond the chivalry codes to show human beings who care for each other and would do everything for each other?

"King Arthur" is a fairly interesting story of a Briton-Roman centurion struggling with his conscience. If they had used other names, it would be fine. But to boast of it as "the true story of Arthur", to dismiss Vortigern and Ambrosius and Uther Pendragon as legend and throw in a bloodthirsty Tristan as true history is preposterous. And I still want to know what the archaeological discoveries are!