But the LA Times polls, which had a unique methodology, predicted it. And Scott Adams gave quite reasonable explanations of why. Any news outlet that didn't give him at least close to a 50% chance wasn't doing their job.
Personally, I made a few grand betting on https://www.predictit.org, because it was pretty clear there was widespread delusion going on.
If there was a 90% chance of winning, it is the 10% which happened. That's pretty clear by how crazy close it wound up being to. Just 80,000 specific votes in specific states are outweighing more than 3,000,000 across the rest of the United States. That really feels like something that had about a 10% chance of happening (or less really).
538 said it was 66/33 or 75/25 or something similar (i forget, but it wasn't 90/10 in favor of Clinton) and they got roasted over it when they don't even control any of the polls.