The disable option is poorly implemented.
One of the reason why anyone would want to disable auto correction is to write in a language for which there is no auto correct dictionary. But then if you disable, you also disable it for english, or spanish or whatever.
this "take it or leave it" approach is not acceptable. They should have enabled a keyboard language layout that doesn`t have auto correction enable, and that way you can cycle through all keyboard layouts tapping on the globe icon (for those who don`t know what i`m talking about, if you enable spanish and english keyboards, for example, you get an additional globe button whenever the keyboard is showing. this key is right next to the space bar.
apple should introduce an option so you can "tap -> english.. tap again -> spanish ... tap once again -> ABC auto correct disabled"
Apple needs to realise people DO write in other languages. For example I write in Spanish and English, which are both supported, but I also write in Catalan (one of the official languages in Catalonia, Spain, together with Spanish) and also hebrew (with latin alphabet of course.. Apple doesn`t deem necessary to allow text to be entered in arabic or hebrew scripts but it doesn`t matter because with auto correct enabled, writing hebrew is a pain, and with it disabled, writing in spanish or english is unbearable....)