Without the ability to hit hard, you are not truly practicing combative martial arts. It is not uncommon to see an individual trained in kung fu enter a fight, using beautiful movement and countless techniques, only to be demolished by the brute strength of a karateka, kickboxer, wrestler, etc. In my humble opinion, if you are not trained in iron palm, you are not really fighting kung fu. His body is hard and cruel, conditioned to be impervious in unexpected ways. So many people get into practicing the martial arts casually these days.
People take a few classes at a local tae kwon do gym and then claim they are martial artists.
They advance through belt rankings regardless of ability as long as they pay their dues. Stay long enough, and they eventually get black belts like some kind of employee of the month award. True martial arts development is not based on good intentions. It is based on skill and ability. Some people should never get a blackbelt, regardless of effort and dedication.