This is from The Economist (March 13, 2004, Leaders: The vision thing) …

“Visionaries get things wrong because they concentrate too much on the technology, and fail to take into account the way it is shaped by social forces as it spreads.”

The article goes on to mention that often the most successful innovations, e.g. the internet, succeed because their inventors …

“made no assumptions at all about the ways in which it might be used, and so placed very few constraints on its development.”