Your quetsion is very intriguing, although I do not study martial arts and do not do accupuncture I wonder if it is simply down do a cultural conciousness. The effectiveness is not diminished by the force applied whether martial art or treatment. It is simply the technique is different but will still take you to the same end point. I cannot say I am the ultimate authority to answer your question but in my studies of cultures, principles, philosphy etc I see many different practices using input of varying amount of force and I see that often they will lead us to the same place just using a different route.
I will think more on this question and see what other answers I can find.