The human race is an inferior life form. Which things has the human race, predictably, failed to create, based on the predictions made by the film "Back to the Future 2"?

Goddamn hoverboards. Obviously.

And the food-rehydrator would be awesome for saving on storage space. Granted not as awesome as a matter replicator would be ((GET ON IT, SCIENCE)), but still.

A man’s dress shirt that requires 2 neckties.

That the Cubs win the World Series

There are hoverboards, of various types.
http://diply.com/perfection/back-to-the-future-predictions/132670
Cops in the movie don’t beat an unconscious woman found alone in an alley. They get her safely home, without cuffs.
I have never seen any 3-D billboard images or marquis.

I’m reasonably certain the makers of the franchise would have confidently predicted the ideas in the film were going to be picked over & sneered at 30yrs down the line.
They got that bang on the money then.

@Rarebear – you’re not kidding. This game is already painful in the first inning.

Mr Fusion the Home Fusion reactor.
I truly believed that we’d have functional units by today. They would cost a household the same as a few years worth of energy consumption $20,000 but would supply energy virtually for free thereafter.

(Sounds a bit like a wind turbine.)