Unfortunately Bruce, and his successors turned the one inch punch into a gimmick. First of all this type of energy has existed since IMA has been around, and second of all Bruce's display of it was elementary at best. Too much time, windup, and "externalism" in it. All it did was push the guy back, and had maybe a subtle internal effect.
There are guys out there who can do the same, with little to no movement, and instead of pushing you back, drop you on the spot.
Bruce was famous for things like this, because of how generally ignorant the Western crowd (even other oriental martial artists) were to this sort of thing. But in China, this kind of thing has existed for centuries. It was like "ooooh aaaah"