To go back to the question. Yes, plenty of people's aikido is excellent for self-defense. The old maxim is, it's about the artist rather than the art. If you want to reduce your opponest to a red mush, aikido isn't for you (unless it'll calm you down a bit first). There is aikido which is excellent for the mind (I won't get into anything else abstract), there is aikido which is excellent for self-defense (when combined with some talent on the practitioner's behalf; I believe that's always a prerequisite) and there is aikido which does both.
I really think, though, that if you want to learn a martial art purely for self-defense, there are dedicated self-defense classes, many of which are of great quality and efficacy. Aikido's fairly slow-burning as far as learning goes- one certainly isn't as "effective" after six months' training as someone who'd spent the time doing something totally self-defense orientated. But in terms of what it brings to the table, I'd far rather have it than an equivalent amount of military close-combat training, etc.
I think I'll leave this to the older and wiser types
Apologies if I've unwittingly ruffled any feathers.
I tend to think of Bullshido as the more rough-and-ready end of the Baffling and Bad Budo fora at E-Budo.