Commercial eggs in America must be refrigerated because the chickens are kept in unhealthy unsanitary conditions. The eggs are filthy and contaminated with salmonella (and other fatal bacteria), thus they must be washed to remove the salmonella. Washing the eggs removes a trans-membrane that normally protects the egg. As such the washed eggs must be refrigerated.
I have a small chicken farming operation (for our homestead) and we don't need to refrigerate our eggs because they don't need to be washed/refrigerated - our coop is properly cleaned and eggs are collected multiple times a day to ensure they stay clean.