I'm sure way back in the day, the creators of kendo were true masters of old-school kenjutsu and knew what they were talking about when they said "ki'... but modern kendo is now somewhat far removed from its roots. A modern kendo master in the standard kendo context saying "ki" very likely means "spirit"; however possibly when they speak in the kenjutsu context it definitely could mean body skills.
I dunno, Howard.... if you saw any of the conversations on this forum a couple of years ago, some of the same offerings about what "ki" meant were made right here on this forum. Depends on what you know, how you use or interpret the term, I suspect.
From what I can see of modern kendo, the physical aspect can be covered with conventional muscle, but the mental aspect has levels upon levels of pure mind-skill ("spirit") which is awesome to see at high levels. Unfortunately body skills is a bit of a third wheel in this particular budo: you don't actually need all that whole-body short power to be really, really good at kendo regardless of your age, physiology etc... unlike no-rules real slice-and-dice combat kenjutsu. So in a way kendo really is a "reduced" version of kenjutsu... but training the mental game more than the physical makes it more relevant to modern life, and great fun too.
I very much disagree with that assessment. It's sort of like you're arguing that all the techniques in Aikido can be done with external strength so therefore the discussions about "ki" as anything but spirit aren't really necessary. In my personal opinion, that would rather miss the point.