There is a reason for that. You know playing an rpg is partly about optimizing your stuff. Using the right abilities, combos with your party if you can, choosing and crafting more appropriate gear for your characters etc. Think out the best tactic in combat. Well you do try to do something like that... I guess.
-Hey Fire Mage in my party, why are you doing this low dps?
-Because i use Frostbolt, duh!
-Why are you using Frostbolt as a Fire Mage? You need to hit the enemy 100x times more whan if you were using your Fireballs!
-Because its boring and i like shiny Frostbolts and i like how cool it feels to cast this spell!
-Ok, mage. I guess RPG-s are for you after all. Keep them frostbolts coming!
If you dont spam Spirit Blade as Knight Enchanter this means you are playing the class wrong. Its like spaming Frostbolt as Fire Mage in WoW. But if you are into things i mentioned above, what an rpg should offer, you will end up mashing the key on your keyboard bound to Spirit Blade. Which is ironic really.
But hey, they nerfed it in multiplayer. Thank Mr. Laidlaw for listening to the feedback.
Perhaps if one is locked into the traditional, min/ max, everyone else uses it, and why bother trying anything else sort of builds, this might be appealing to some. But based on the feedback, it wasn't, so I offered something possibly a bit more versatile, and enjoyable, at least from another POV.
Being able to kill easily at range or in melee is appealing, as is being able to control the flow of battle. Static Cage works well to center other AoE's, preps possible combos, and place nominal dmg on the enemy. Meanwhile, Dispel, Chain Lightning, and Energy Barrage can dmg, detonate possible combos, and offer other effects to better manage combat. Now I play with all Floating Text turned off, so I do not know how much damage, but the ever changing pace of battle indicates that such tactics are effective; that and the dead enemies.
But every now and again, something might get close, so a Fade Cloak and Spirit Blade are handy on such occasions, and seem to help spoil some of those plans. This type of tactic also worked well in Skyrim, and to some degree; DAO. Both Mage and Rogue designs were made to have a longer Kill Zone, and seem to have been effective.
But if one wishes to spam the spell of choice, go for it; prefer other options here.