The real reason that GDP was revised downward was because economists have no clue. Whatever forecasting methods they use never seem to be able to get it right. Sure, if you ask 40 of them to predict some future event, one or two by chance may get it right but, let's face it, they might as well cast bones.
At the center of this inability to predict is a careers-worth of misunderstandings.
Here is the reality for the American economy: the current Congress and President are a disaster for economic growth and job creation. They are spending too much foolishly (perhaps that's redundant), demonizing business, raising taxes, increasing regulation, and creating uncertainty about the future of the economy.
Until they understand this, or until we throw them out on their over-educated backsides, the U.S. economy will not recover.
I pine for the days of legislative gridlock.