. . . I know several aikido people whose response to a question about atemi would be, "you mean you're not using [that] atemi?" Then there are those dojos to emphasize running only in the effort to chase down your opponent because somehow he escaped...
As a general rule, I feel it should take one to two years of training in mainline aikido for someone to be proficient enough to handle typical unarmed altercations.
Taisabaki, kyuzushi, and atemi are, in my opinion, more important than pulling off an actual technique -- especially early in training.