Fred,
after I posted this, I saw your post and felt a bit silly. My apologies for the repeat! For those interested:
http://forums.uechi-ryu.com/viewtopic.php?t=19900
Jorvik,
54 isn't really old! After all, I plan to live to at least 100, so that's only 1/2 way there!
But I find your thoughts interesting. As for weight training/circuit training and machines...I, personally, feel that machines are popular because they're a) cool toys b) easy to learn/use c)many think it forces perfect form (I disagree).
Machines have thier uses, but they are made to fit a set range of body types...and the adjustments don't always fit a person properly, and that can lead to strain and injury. Being a rather short individual, I've had several machines that simply hit my knees and back at the wrong places. Most folks never adjust the machines, so they end up with far form perfect form/training/technique. But for a beginner, it's a great way to start, and some machines have some great uses!
Also, free weights require more usage of stabilizing muscles, so you get more bang for buck...can you tell I'm a fan of free weights over machines?

Although, I do believe some machines, used and adjusted properly, are GREAT tools, as mentioned.
back on topic...
like any type of weighted exercise, I could see misuse of kettlebells. I think the excercise itself, with or without weights may have some merit though. Fred's drill is very similar, and uses no weights.
I just think the concept is useful, and it does appear to be a common concept among oriental martial arts....as it should be.
Reality probably does mean "ground...bad", but stuff happens, so training for this eventuality is probably a good thin, IMHO.