I was taught that, since potentially 50% of one's practice is spent as uke (a lot of accumulated time over the years), it makes sense that that time and effort would be best spent striving towards the achievement of one's Aikido goals. In that sense, Uke and Nage are not different . . . there is no distinction between "uke" and "nage" outside of the kata, and since "there are no kata in Aikido" . . .
(Quiet Peter . . . just take the fall
Please notice that I left the goals of Aikido open for the individual to define according to their time and circumstance . . . as per O-sensei's example.