They are distance damage dealer, it's already something. They have plenty of tool to damage while moving. And they have, yu said it, a pet (very annoying for healers if you know how to control him).

Black mage are strong too but need some prepa to be able to burst someone down and need to cast. Archer are completely devoid of any protection skill (contrary to ninja or Black mage) and their stronger shot can't make critical hit and requests that casting stance be activated. If i make my full rotation without interruption as a archer, it won't kill a mage even if some of my blow are critical. And to do that i have to be almost motionless and not attacked.
It's still enjoyable to play in pvp. So i don't see why summoner could not be nerf a little.