While practically speaking, if such words are used often, it would be handy to have them in the autocomplete lists. However, UX is more complicated than simple mechanics of efficiency.

The brands releasing such software would want to prevent any association with this kind of language. Having swear words in autocomplete features could suggest that Apple or any other organization supports and encourages their usage. Any such association damages their image and might affect user's appreciation of the product. The reality may be that f*** is so commonly used that typing anything that starts with an f will make it show up as a suggestion. This has to have an affect on the impression the product makes. While it's somewhat ok for autocomplete software to be dumb, it's probably not a good idea to make it both dumb and offensive.

In fact, as Deer Hunter helpfully illustrated, for every user helped with a quickly auto-completed swear word, there will be many offended users. Sometimes quite severely offended.

If such words are used often, it would be handy to have them in the autocomplete lists. However, UX is more complicated than simple mechanics of efficiency.

The brands releasing such software would want to prevent any association with this kind of language. Having swear words in autocomplete features could suggest that Apple or any other organization supports and encourages their usage. Any such association damages their image and might affect user's appreciation of the product. The reality may be that f*** is so commonly used that typing anything that starts with an f will make it show up as a suggestion. This has to have an affect on the impression the product makes. While it's somewhat ok for autocomplete software to be dumb, it's probably not a good idea to make it both dumb and offensive.

In fact, as Deer Hunter helpfully illustrated, for every user helped with a quickly auto-completed swear word, there will be many offended users. Sometimes quite severely offended.