Don't know who's responsible for the various myths that go around, but in my years 17 odd years in Japan, there's one that I've heard often. "Japanese students can read and write English, but they can't speak and listen." That is a myth that has not rung true after associating my students. The reason I mention it is because I evaluated my students today on material that they have learned this semester. There is a spoke section as well as listening, reading, writing and culture sections. They do pretty well when it comes to speaking and listening, but have a very difficult time reading or writing. (All of my unit exams are on my web site if you care to look.) When I say, "...a difficult time," I mean that they can read a word on the paper, possibly sound it out, but then have difficulty relating it back to the katakanized word they know. For example, in an exercise we were doing in class today was the word "gardening." A fictional character had the hobby. One student asked what it was, started to sound it out himself, and it didn't register with anything he knew. I said it for him, and he made the association between the word I said and the katakana version he knew.
My students rely heavily on what is written on paper, and have a hard time doing without it, but when they no longer have a paper to rely on, do very well at producing and understand language. When they have to go back to the paper then, and associate the words they have been saying with what is written on the page, there is a gap. There's a lag between seeing the word on the paper, sounding it out, and relating it with what they have been listening to and saying in their speaking practice. They have seen the words before, but the way they pronounced them before and after the speaking practice are different. It is great fun to watch them make the connections.