My early aikido training included soft atemis (to prevent injury), though it was necessary for Uke to 'block' them with a hand to stop himself getting constantly poked in the groin or slapped across the face.
However, on a recent course I noticed the instructor was very averse to Uke blocking atemis (and therefore they were even softer or not even touching). Obviously I found it nearly impossible to get out of years of habitual atemi blocking. But the instructor had a point. He said that it 'closed' the Uke (and it also prevents uke seeing what Nage is doing in many cases). On another point, is it realistic to expect that someone could block an atemi in a real situation. (My view is yes).
What do you think; block an atemi and have a closed Uke or don't block and risk pathetic atemis being exhibited and students developing no quick reaction to small atemis?