I mean, I thought (and still think) that Twitch was a terrible business idea - something I'm clearly very very wrong about. Equally, there are dozens of business ideas that I thought were fantastic, but are dead in the water.
Sometimes it's good to acknowledge that your foresight can be wrong. I think engineers in particular can be overly pessimistic.
Why not occasionally take a risk on someone else's gut feeling? You won't always win, but "losing" means enjoying a cushy, well-paid office job for 2-3 years before moving on the next thing. It's hardly the end of the earth.