Here is a poll I dug up from the poll archive:
I think it's all dependent on how one trains.
If one trains in aikido to develop ki, harmony, etc., I think atemi is superflous and perhaps even counter-productive.
OTOH, if one is training in aikido as a budo, a martial way, I think awareness of, and therefore practice of, both giving and receiving atemi is *required*. The openings for atemi _are there_. They have to be acknowledged and dealt with.
But that's just my personal opinion.