Why ever give up the initiative?
Action always beats reaction. Stepping in a smashing an unsuspecting/nonaggressive person in the face would not only not be Aikido, its also a crime. However, lets say a "Drunken Yahoo" confronts you and takes a karate stance and announces that he is going to beat the hell out of you. Why wait, pretend to attack with a shomen to the head and when he responds with a high block he sets himself up to be taken down quickly and quietly with ikkyo. The alternative is to wait and see if you can execute effective technique from whatever attack pops into his head. Initiative is survival and taking it does not mean leaving the "moral high ground."