One thousand years of practically uninterrupted peace under Celestia's rule... And then, in less than half a decade, half a dozen world-threatening monsters suddenly crawled out from under their rocks and tried to overthrow the kingdom. Nearly every time, the same six mares eliminated the threat.
While that makes for a great story, and newspaper editors loved the idea of super-ponies empowered by the magical bonds of friendship, the average noblepony found this idea somewhat concerning. The security of the entire nation depended on six individuals. Following Tirek's return and the widespread damage he caused, the nobles resolved to create a secret division of the government to anticipate and counter any future threats of an extraordinary nature.
From this idea, F.R.I.E.N.D. was born. It was a collection of Equestria's best and brightest, backed by considerable wealth and dedicated to the defense of ponykind against anything that imperils it.