I think part of the bad english is the emphasize put on repetition in Japanese (or generally asien) schools. You may learn words, but even with 2000 words you may not be able to build a sentence.
I myself had about 2 years of english. Bad marks. Then I played english Daggerfall. Lots of text. Learned a lo. Don't ask me how hard it was to find out what gotcha meant without internet back in those times.
Yeah, not having an opportunity to make original sentences that actually pertain to real-life situations is a big problem. Daggerfall? I don't know that game. I'll have to look into it.