The end result creates what sounds like a massive amount of different types of spells, but actually translates to supposedly "unique" spells that are actually just variations of the same spell with changes to how strong the spell is or how long it lasts.
If all you did in the spell creator was adjust the numbers then I can see why you would not miss it, and in my opinion you should just not use it.
The fun of the spell creation system was not in adjusting the strength or duration, it was in the ability to combine multiple effects into one cast.
Without spell creation in past TES games you would never have been able to make spells like:
Frenzy + Invisibilty - start an all out brawl amounst enemies or even just for fun pub fights.
Elemental Resistance (self) + Elemental Damage (self) 10ft - PBAOE fun
Drain Strength + Damage Strength + Burden - lock down a melee and focus on his friends.
Drain fatigue + Damage Fatigue - watch your enemy suffer a bout of narcolepsy, and better yet you can repeat the process and watch them get-up/fall-down endlessly for hillarious fun.
Dispell + Silence - strip that caster of his buffs and shut him up to prevent his heals.
Fortify Strength + Feather - when you really really need to haul 5 briastplates back to town to satisfy your loot-whoring desires and dont want to make 5 seperate trips.
Disintegrate Weapon + Drain Unarmed - take the weapon out of the equation and make only weapon left ineffective.
These are just some examples of a basic system that could be used to make many many varied spells.
Given there are only going to be around 80 spell effects (confirmed and same number of effects as oblivion) without a spell creation system players would be getting seriously short changed in terms of variety.