Oh -_- Runescape.
Runescape wasn't that great anyway, and you couldn't summon.
Even if there is a "lack of summons" in OoL, compare it to other huge MMOs such as World of Warcraft. Warlocks have 5 Summons.
Even so, you said "spells", not "summons",
Ok, take this picture, take runescapes magic spells (all eighty something) then compare them to eleven (I think) summons. Which Mmorpg will the magic lovers go for, Eighty spells or 11?
Do you really think we would leave out spells?
You can't really expect to have 80 summons from every single damn monster in the whole Zelda bestiary.