Hey Kwang, I'm dealing with this issue right now. I'm a Wing Chunner and over the years I've been repeatedly warned against lifting weights. Various instructors from my old Chinese sifu, to my current instructor who keeps up on modern research into kinesiology and training techniques, have told me to lay-off the weights. They all say that heavy weights lead to heavy muscles and a massive quality that interferes with the kind of "sensitivity" and light, quick upper-body movement required for good Chi-Sau.
Now I watched your video and have seen other martial artists (Van Damme comes to mind) who were heavily muscled, yet fast, stretched and even acrobatic... at least with their lower body. On the other hand, Chi-Sau requires a great deal or upper body flexibility, range of movement, and a very light touch. I have to say that as I've built up my arms and shoulders, I have fallen behind my peers in the ability to quickly sense and redirect my energy. It's a very subtle art and in spite of many years of experience, my heavy arms seem to be holding me back. We are discussing this right now down on the Wing Chun forum if you'd like to weigh in on the topic.
Now to get back on topic. How real men fight? That's dueling. A contest of honor based on rules, and etiquette... I don't duel. If I fight it's because I don't have a choice. That's self defense. And as others have already said, when you are fighting to defend yourself and your loved ones only one thing matters-- winning.