Then I say you need to stop getting your information from websites. I described the principle behind how to strike.
Which is completely unrelated to the actual techniques I've been taught. Which only goes to show that the one-inch punch is misunderstood by a lot of people.
You want to flash a picture of Bruce Lee here, then you should already know that what I described is what he taught as the way to strike something. So, why is there a difference in terminology if your training comes from Lee in some way?
What you described has nothing to do with the way he taught to throw the one inch punch. Bruce developed the one-inch punch by combining Wing Chun floating punch techniques with boxing techniques, in order to build up power in a very short distance. You don't punch "through", you punch "into" an opponent, using depth in the same way some people use extra force. Combined with the surge action invovled, you explode into your target, and you don't go "through", you go at a very precice depth. Going through robs your stike of power, in the same way that overpenetration loses a lot of power from a bullet. If I do the technique incorrectly, I punch through, and the other guy goes flying. If I do it correctly, he falls down as he tries to reinflate his lungs. (And no, I don't do it correctly except by accident. Which is why I need practice.)
As for the photo-- why is it so surprising that I know some of those people? That photo was taken in Seattle, around 62. Only 40 years or so ago, not that terribly long; except for Ed Hart and Bruce himself, everyone in that photo is still alive. Jesse Glover and Taki Kimura still have schools in Seattle, for example.
Too little fat - like the bodybuilder - and your muscles themselves have no protection. Too little muscle - there's no one in the comparison to represent this, since the sumo is also heavily muscled - and there's nothing solid enough to slow the impact on the internals. But if you have some sort of desire to get a notion of what the world's best fighters try to make out of their own bodies for the purposes of fighting, you'll see that it's not an increase in fat, but am increase in firm, toned muscle, which is superior for health, fitness, strength, endurance, and injury protection.
Fair enough. I've never gotten into a match of any sort with someone who had only fat with zero muscle. When I've had matches against people with lots of muscle with little fat, I tended to win very readily, as they got hurt; when I fought the guy with lots of fat and lots of muscle, I couldn't do a damn thing.
A sumo in a fight with a standard martial artist, however, tends to go to the sumo. Bigger size and weight is a huge advantage if you know how to use it, and they do. Compounding this is the fact that most of your strikes simply don't do much to him; the fat absorbs the blows. The same strike that would have been effective against a similar, nonfat opponent, is now ineffective. Any martial artist worth his salt will say that he would greatly prefer to fight a football player than a sumo, because of that body fat.
I haven't trained with any famous martial artists. I can look at pictures of them, though, and when I do, I don't see fat people.
Look up a recent photo of Leroy Garcia. Is the guy's gut absolutely huge? Yes. Can he still move faster than any of us? Hell yes.
And you completely glance over what I'm saying about your comment that fat is a key component in our ability to defend against impact. It's not. You are wrong. 
