Maybe with the change in the political climate (end of the cold war with the Klingons, disappearance of the Romulans) Starfleet decided to cut back on military programs. In that light some of the oler designs might be worth keeping around or bring back. Sort of like what the US did with the IOWA class Battleships. They were obsolete since WWII, and decomissioned. Then 40 years later they get put back into service. While the Iowa class was even more outdated in the 80s that it was in the 40s, it still could fire a shell over 25 miles. The Connies can still do all the things they were designed to do-they just aren't the "best ships in the fleet" anymore.Originally Posted by TFVanguard
Performace wise, they do match up well against some of the smaller craft in Starfleet. Not much difference between a Connie and an Intrepid or Nova class. If you convert thier speeds over to the new scale they are pretty fast too ( Not many ships can cruise at wf 6.5 MCU even in the DS9/Voyager era).