538 didn't fail to read data properly re Trump's nomination. Trump was a new phenomenon with no history to build a model from. 538's mistake was guessing instead of admitting they had insufficient data -- which is bad behavior, but not because their preferred methodology is bad.
Bull. Their polling based model performed okay (although, at least through Super Tuesday when I looked at it, his polls-plus model didn't outperform his polls-only model, and neither significantly outperformed the RCP weighted average of polls). What failed during the primaries was Nate's "Party Decides" punditry.
538 didn't fail to read data properly re Trump's nomination. Trump was a new phenomenon with no history to build a model from. 538's mistake was guessing instead of admitting they had insufficient data -- which is bad behavior, but not because their preferred methodology is bad.