Hi George sensei,
I train with and am assistant instructor for Tama sensei in Vancouver. She has always been pretty clear when she teaches that aikido is undoubtedly a martial art. While atemi is not always explicitly shown when we demonstrate, as instructors (other senior students included),we understand that they are implicitly present. I think atemi is most explicitly shown, by all who instruct at our dojo, during the demonstration of basic waza ie. ikkyo and sankyo omote and kotegaishi, to name just three, to provide a distraction to uke so nage may apply the technique.
I think that the bottom line concerning atemi is the fact that is intergal to aikido waza in a very pragmatic way. Most aikido waza would not be possible without atemi, I think. While I'm the first admit I don't train like this all the time there is something to be said for training to create openings and opportunities via atemi.