Eventually I will write an article of my own on this topic, but for now I will reference someone else.
A quick Google search (“martial arts and strength training”) gave me this wonderful article. For me, the most important part of this article can be found in the following quote because it explains why martial artists NEED strength training as a supplement to their martial art training; here the author is clearly describing the plateau effect:
“In the beginning, the skills that make up a martial artist’s training will actually improve strength. In other words, throwing side kicks makes the legs stronger, and so on. But after a time, the body will habituate to throwing those kicks, and you don’t get any stronger.”