All things are relative when it comes to atemi, imho.
When a person is first learning aikido, they need to learn what an opening is. Standing in a horse stance with the jewels sitting right there is a good way to get racked. Newbies need to understand these things.
As training progresses, vital points need to be pointed out and shown why they are important. When sensei is cutting someone over into ikkyo... that's one thing. When sensei does the same thing, but first captures the uke's balance with a good atemi... that is another; and it should be taught early on. Expected on tests? Maybe not... but the student should be exposed to it.
As time goes further on, resistence is applied by the uke to ensure that the nage (student) is in fact doing the technique properly. Atemi-waza is very effective here and though you do not HAVE to land a punch, that one is indicated should be sufficent for the uke in "practice" to react to.
Now then... advance practice SHOULD involve atemi-waza. Why? A) So nage can execute it and get it to work effectively and B) So uke can defend against it and protect himself at all times, even during hearvy practice (i.e. randori, jiyu-waza, etc.)
Okay. Let's look now at the question of
or Aiki. Does atemi-waza go against the desire of the founder and his "Art of Peace?" Some say this is so. I say if you subscribe to that line of thinking, you are kidding yourself and are not learning aikido. That's nambie-pambie way and not THE Way. See, that's the problem with society these days: people want to "counsel" bullies and psycoanalyze them and find out that they were abused as a child and that THAT is why they bully kids, etc. etc. Bull. When I was growing up, when you defended yourself and stood up to the bullies, you earned respect. Sure, you both went ot the office and got paddled, but you didn't have to deal with them afterward
"Spare the rod, spoil the child." I hated that as a child... but now that I'm grown and can look back on it, I see it as a nessecary in the world.
Did I get a bit off the subject? I don't think so... just looking at a much broader picture. Hope you can see it too.