That is not a very accurate take on boxing defense. A lot of their defense uses head/body movement and footwork to carry them out of the way, both of which are useful skills for SD.
Actually it is very accurate. I never said it was all encompassing, but the statement is quite accurate. I grew up in an era when Western Boxing was considered the primary self-defense vehicle, before the martial arts explosion, when there were boxing gyms everywhere and it was even a apart of boys high school gym. I am quite knowledgeable in Western Boxing as was my teacher who boxed extensively before abandoning many of its elements. I "boxed" in high school, however I do not personally consider this experience as true competitive boxing. Everyone in my class boxed.
I know for a fact that the vast majority of kenpo people would benefit from some boxing training.
NO, what you know for a fact is that YOU BELIEVE that the vast majority would benefit from some boxing training. You have no way of quantifying in actuality the statement, however I too believe as you do that most would benefit. I never disagreed, but only pointed out some documented serious considerations that were shared by my teacher, Bruce Lee, and a great many other people as well.
But consider what is now called MMA has been around for centuries, and western boxing for at least a couple of hundred years. It is only because of the popularized televised sporting aspect that we are even having this conversation. It was no different when I was growing up, which included Western Wrestling which was as MMA is today, in the mix as well.
People have always had a choice, and gravitated to what they wanted for various reasons, many that go beyond kicking someones butt. But the vast majority of the greats that I grew up with and learned from all had elements of what some would call "boxing" as a part of their routine training, without having to become boxers. Also just as interesting is, almost all of them had boxed for a period in their own development. Also consider western boxing came from eastern boxing, which has many of the training elements present in the modern version of western boxing and more, before there existed western boxing rules designed to make it civilized and tame in comparison.
So the blending of "boxing" with other martial arts is not new and the good ones have never considered it an "either or" proposition, incorporating what many of the youngster call boxing and mma already in their art. They always had balance in what they did, and in fact that is what Mr. Parker and Bruce Lee were alluding to. Bruce Lee incorporated it and Mr. Parker has elements of Chinese and Western Boxing even in his commercial version of Kenpo Karate. It's already "in there," and any deficiency of "kenpo" is one the teachers. The key was and has always been about "balance."
It is only some of the youngsters who have this "warrior mentality" in todays society, where getting beat up in training is a euphemistic badge of courage. Today many have to go to work the next day and can't afford to get hurt recreationally, or do anything that might affect their ability to pay their mortgage, or their children's tuition, or even how they look at their job. Yeah I was young and dumb too. I did the whole "tough guy" thing, broke boards, etc all while growing up seeking and exerting my manhood, as did my teacher. Fortunately, he stopped me from doing it as long as he did.
We need to cease making blanket statements about what "kenpo" has or has not, and begin an examination of what we as individuals choose to do, and stop painting what we have been taught with the broad brush of everyone else's "kenpo" experience sir. On any giving night peeking at my people, you just might think they were western boxing, or maybe it just looks like it. It happens the roots of my training and teaching, predates "western boxing."
Agreed again. Just because we mention boxing, doesn't mean that we can't modify things, such as we see with MMA. They're adding a bunch of things, adapting as needed, etc. Actually, sometimes this is how I do my sparring. Good stuff. 
