The techniques of Aikido are there to develop aiki. They are not really techniques of self-defence. But if you have a measure of some aiki, and put it into say, Jujutsu, then you will have something. Otherwise, even Jujutsu is just 'crunch uke with levered force'.
The techniques of aikido are used to develope aiki but are not for self defense. Therefore aiki is not for self defense? If aiki is for self defense then why can't you put aiki into the Aikido techniques and have something?