I really don't think he was around long enough to 'influence a generation' tbh
We qualified in style and then, Capello started acting weird. He was trying to get people out of retirement. Hang on, we just qualified nicely, what's all this. The build up to the World Cup we were turgid but you think 'ok, well, it's winning football'
I think there needed to be a bit of a course correction from Sven's 'inmates running the asylum' style but Capello was a bit too far in the other direction. The players clearly baulked against it, I don't think he'd earned the ability to put these things in place to quite such a dramatic level, imo