I'm not a Kenpoist, but I find the handshake defenses in most arts silly as shown literally but an excellent way of learning some good principles of locks and of getting an immobile body to start moving--an often overlooked subject area--so as to have some motion with which to work (i.e., Newton's First Law of Motion). To my mind these wouldn't truly start as handshakes--if the handshake is that dangerous, throw a left cross, otherwise, use your left hand to poke him somewhere--but rather as a grab, most notably in a knife defense. You're not shaking the hand, you're covering his knife/gun/etc. hand.
I think to say that Jeff Speakman is ignorant of (significant parts of) Kenpo based on this is a bit extreme. Surely those items to which you refer might be taught elsewhere in his curriculum? There must be other ways to teach them rather than via the handshake?
Well sir, I agree with much of what you said, however when speaking about the depth of information of Kenpo Material, the error in thowing it out, and in particular the lack of knowledge, I am somewhat an expert.
Mr. Speakman's tenure in Kenpo was relatively speaking brief. He earned his black belt under Larry Tatum, and "worked with" Ed Parker for the movie Perfect Weapon and was a 4th. While Jeff is indeed talented his total tenure in Kenpo amounts to about 5/6 years prior to Parker's passing. I also, in this case, happened to be priviledged to what he was taught.
Even more significant is the fact that he was for a short period my student, and has a diploma with my signature. Yes he is very talented and intelligent, but there is much he has not seen, or been exposed to, or is actually interested in.
The Kenpo 5.0 material by his own admission, is a collaboration between he, and one of his own students, (Trevor Sherman; who was a former student of Sean Waugh), and I commend him for seeking his own path in the art. I like the idea he is addressing these things from his perspective, and I really like the physicality of his primary students. Good for him. But I am also uniquely qualified to assess and comment on the particular question at hand being his however brief instructor, and kenpo senior of at least a quarter of a century.
Mixing conceptual sport grappling with Kenpo is not new nor unique. In fact, if you will, the "Original Kenpo" out of Hawaii was just that with a significant Danzan Ryu influnce through direct instruction from Henry Okazai to Kwai Sun Chow. While a great deal of that material was removed, adjusted, or reinterpreted for mass market appeal in coming to the mainland, Parker never loss sight of the information nor many of his most senior students like Chuck Sullivan, Dave Hebler, Steve LaBounty, or the late Dave German. With good friends and collaborator reminders like Wally Jay and Gene LeBell, this would be difficult for Parker to do.
As for the "handshake" techniques, there are a multitude of ways of examining them. First you could consider them what I call, Gendar Specific Assaults. That is they may be more likely to occur between the sexes (male to female), and therefore needs to be significant addressed.
Secondly they, regardless of gendar typing, present a unique perspective that encompasses in some cases, a pain mechanism as well as control manipulation possibilities that are unique in defense scenarios. You could also consider them from the perspective of them actually being "cross wrist seizures," that may occur in conjunction with other physical actions. And probably the most interesting is as it is in the intracacies of the Chinese Arts where all is never as it seems, and a lesson of body mechanics, body posture, and skelatal alignment in conjunction with specific indexing of major Propriocept Nueromuscular Sensors that can be manipulated to a position and circumstance of advantage.
As for simply, "throwing a left cross ..... or poking him somewhere with the left hand ...." I'm not entriely confident that is as easy as it sounds when faced with a committed attacker who is either "holding" your wrist, or shaking your hand" with additional physical assaults also a part of the scenario. Having been on the end of a determined suspect with only one handcuff on, taught me years ago that just because you got one arm, don't mean you are not in jeopardy or that you control the other sir.