Nate Silver gave the eventual winner a 30% chance of victory, and his prediction for the popular vote was off by only 1% for Trump and 0.5% for Clinton. That's a damned good job if you ask me.

I can't fathom people who look at the results of this election and conclude that the polls are all horrible. They got very close to what happened. Many places took those poll results and interpreted them far beyond what they should have, saying Clinton was a lock when she wasn't, but that's a different matter. (It seems like they assumed that errors in swing state polls would be uncorrelated, thus vastly underestimating the chances that a lot of them would flip together.)

If you were trying to sway the election for Clinton, talking about how her victory is assured would be a bad way to go about it. That just encourages her voters to stay home. If the polls were biased that way, and if it was a deliberate attempt to sway the election, then if anything it would be an attempt to sway it for Trump. Which really doesn't seem likely at all.