To say "Westerners missed it" does not have to mean every-single-person. But on the whole it is not only accurate, but those exact words have come out of the mouths of some serious teachers after feeling these skills.
Actually, I said "most westerners" for the very reason that I did not mean "all westerners".
I agree with most of what you say, but I'm personally tired of beating that particular dead horse about people who don't get it; I'd rather just work with the ones who are interested, some of whom actually get it and will be the mainstays of the next generations.
I had a teacher in Denver years ago who had very recently come over from Beijing and occasionally he'd ask me to take over his Saturday morning public class if he was out of town. I'd help with whatever they happened to be working on, but one time I asked the teacher why he had never showed them how the body moved (with ki and kokyu power), since that was obviously the basic stage they never got past, no matter how many "forms" and "applications" they worked on. He just shrugged and said, "They either figure it out or they don't". I used to be mildly disapproving of that attitude toward his students, but the older I get the more I see how much it saves time and energy.
Notice how few people really show much of an interest, even in the case of, for instance, Ushiro Sensei's teachings even when they're recommended by Ikeda Sensei. Granted, I don't think Ushiro is clear in his exposition and how-to's, but still there's nowhere near a lot of interest even in a Japanese 'expert' who is recommended by a big name in Aikido. Either they figure it out and start looking for information or they don't. No use cudgelling anyone, particularly if they're sure they know the "secrets" already.
There will always be sheep and there will always be goats and there will always be more sheep than goats. It is the natural way.