People have different takes on what is art and what is just fighting. Frankly, I think the whole thing is ridiculous. Every martial art, no matter how you dress it up, is designed for fighting. Plain and simple. Yes there is sprituality, humility, respect, but that depends more on the person. Someone can learn boxing and from it learn humility, respect, skill, focus, all the things that a more traditional art would give you. Then you can have someone who trains in a traditional art who's nothing but a punk. Whos to say it's not a martial art just because there are no flowery forms or there isn't a figure of General Kwan in the school?
The problem is that people have gotten so far away from the original intent of martial art and each generation gets more and more watered down. If you say that you like to practice full contact fighting, then you're called egotistical or violent. I guess the true essence of martial art is only practicing forms, "dead" drills, and throwing out a few Chinese proverbs. But Heaven forbid, you should never practice actual fighting. That's only for savages. So to sum it up, Wing Chun and in fact every martial art is both an art and for fighting. And if you ever come across a sifu or teacher of any art who tells you otherwise, he's either an idiot or a liar.