The experts, expert though they may be, simply cannot centralize decision making and come up with better outcomes than individuals making the best decisions for themselves. From Kevin Duffy at lewrockwell.com:
In order to navigate an impossibly complex world, we take shortcuts, build logical frameworks and adopt ideologies. These are lenses through which we view events, our own reality in a sense. Over time, these lenses become hardened and extremely difficult to change, regardless of the counter evidence.
There are essentially two views of the world: order and chaos. Some see a natural order: the food chain, pecking orders, innate behaviors, complex adaptive systems, natural selection. Others see chaos requiring direction by a group of experts.
At least when it comes to economic activity, the overwhelming majority adopt the chaos view. They fail to grasp Adam Smith’s “invisible hand” of mutually beneficial trade, Friedrich Hayek’s “pretense of knowledge” with regard to central planners, or Frederic Bastiat’s “seen and unseen costs” concerning the unintended consequences of economic policies.
Interventionists dread uncertainty; above all, they fear losing control.