People will just get upset about anything, I guess.

Autocomplete is fraught with peril. Maybe I'm actually trying to type "duck." Maybe I'm talking about my "new oven" and I'd really like it not to think I meant to press J instead of N. (True story.)

Autocomplete is a low reward, high risk endeavor. If you get it right, you've helped the user slightly. If you get it wrong, you may get the user in serious trouble and they'll be telling everyone about how "my iPhone got me fired." But you have to have it, so they'll try to reduce the odds of a bad outcome by refusing to produce various phrases that could be problematic.