Even without considering historical accuracy, after a few viewings, it becomes clear that the film is not well made despite Taymor. I think at the time it was an awards darling because, though it seems much more pedestrian now, a studio system film about a female Mexican cultural icon was even more unlikely to see the light of day then. I remember discussion around it highlighting its progressive nature, so that likely framed reception of the film, despite the occasionally clumsy script and at times loose interpretation of the subject matter. To be honest, when I saw this link pop up on HN, I immediately thought of the film as an example, rather than the Barbie (which is even worse, but oddly, I can't verbalize why).
As for Weinstein, that attributed pull-out quote, if accurate, stands alone to demonstrate thought behind the portrayal. I'd say it's fair.
Many figures are tough to interpret beyond death, to be fair, and maybe we're all wrong about her. Who knows. Arguable she'd find us discussing it amusing.