The worst thing about dubbing is that it's more important for the translations to have roughly the same length and correspondence to the original mouth movements than to be accurate. So the original meaning is often altered, and you don't even know it because of course you have no easy access to the original most of the time. But unfortunately Germans are so used to dubbing that subtitles don't really stand a chance. There are a few cinemas here and there that show original-language movies with subtitles, and on TV there was one experiment that I'm aware of a few years ago (on Pro Sieben Maxx) to show TV series with subtitles, but it was cancelled after some time. AFAIK it's also more expensive to secure the rights to show English-language content compared to dubbed content.
As others have said, it is better to expose kids (that can read) to the original language plus subtitles.
So in other words, your solution while technically great is pedagogical not wise. A typical geek approach to a problem ;)