Everybody knows books For Dummies, e.g. Sex for Dummies or Linux for Dummies.
So in Russian it translated as Для чайников, literally For Kettles.
Interesting that Russians call stupid and churl people also Cattle (Быдло)
In my opinion
1) Kettle and Cattle are pronounced almost the same in English.
2) Kettle and Cattle has almost the same meaning in Russian translation.
