The problem with Oblivion spell making, it felt too much like math. You take x and y and mash them together and it costs z. It was very spreadsheety and didn't feel magical at all. Until you can think of and develop some crafty way to create a spell-making system and still have it feel magical, I don't think it should exist.
It wasn't complicated at all. In fact, that is the magic in magic. A tangible representation of the Arcane, through study, philosophy, Ethos, and scientific logic. The Spell Making Altar represented spell creation and manipulating the Magicka of Mundus on an intelligent level. Whether spell creation was mathematically difficult (requiring actual 'intelligence') or not, which it wasn't. Since it was, and RPGs are, representations.
Spell Creation allowed outside the box thinking, personal customization above and beyond niche archetypes, new strategies, play-styles and a feeling of corporeal accomplishment, creatively.