If you think about it, it really makes sense that Uke is in reference to the Japanese martial arts term.
In Kendo Kata's (for example) the Attacker (Tori) attacks the Defender (or reciever, Uke) who gets killed (lol).
Howver, the role of the Defender is not just to recieve the blows, but (in theory) also to teach the attacker.
And I am sure you guys agree that by practicing on Uke, you can also say that he is (in a way) "teaching" you.