Wing Chun is one of the most prolific kung fu systems to spread outside of China. Its popularity exploded in the 1960s in response to film portrayals. Up to that point, there was greater awareness of Japanese styles attributable to US soldiers' involvement in the region. Were it not for those pop-culture references, we may not have broad access to Wing Chun in the west today. In fact, a great many systems of traditional Chinese martial arts died out or went deeply underground during Communist China's Cultural Revolution. Most or all kung fu systems were in their time used, taught and promoted to support one side of a political dispute. Wing Chun and White Crane specifically were Ming loyalist systems.
The downside to western interest in Wing Chun is that it spread very quickly and broadly and today it is not all the same. Much of it has been synthesized with techniques and ideas from other styles and in the process, the principles have been lost, misunderstood, or glossed over. In parallel, lineage squabbles started between branches claiming to possess exclusive purity in the style. An unfortunate distraction, though without it we may not have the system at all.