Except that kendo isn't geared totally around shiai. Some people who practice kendo never compete. Nor is keiko geared entirely around preparation for shiai.The thing with Kendo, though, is that it is geared totally around keiko shiai, it'd be like training in BJJ without ever rolling, just drilling a couple of positions and locks. Yeah, you can learn a lot of Kendo without sparring, but that's not the same as training Kendo. Of course, we're up to a semantics game now... and it largely comes down to personal interpretation...
Again, this is all hypothetical, but essentially, the element of sparring would be jigeiko, not shiai geiko. Ji geiko is free sparring where the student can practice techniques with an opponent in undirected practice with no pressure to win.
Why someone would be unwilling to participate in ji geiko, assuming that affording the bogu is not an issue, is what I would want to know. Is it a fear factor? Do they feel unready? Are they embarrassed? Do they have severe asthma and are under doctors orders not to do that sort of thing?
Delineating my students into 'he's doing kendo' and 'he's just practicing sword strokes' does not interest me. Within the art, everything is kendo. If you practice sword strokes at home to a youtube video, you're practicing sword strokes to a youtube video. If you are training at a club or under a sensei, or are practicing what you had learned when you did so at some point in the past, then you are doing kendo as far as I am concerned, regardless of how much of the system you have immersed yourself in.