We play the way we play because it's our best chance of success. The fact is that we don't have the backlines of Australia, NZ or even France. If we commit ourselves to playing quote-unquote "beautiful" Rugby we'd come badly second, but maybe get a few patronising comments from people like Henry & Jones about the fact we're at least trying to play.
The problem is that England don't even use their forward platform to TRY and score... From a rolling maul, a pushover try, whatever... Honestly, if England win this World Cup it will be some kind of daylight robbery. I'm happy for English fans, especially someone like you who went to Twickenham regularly during the last four years, but rugby is in a ridiculous state of affairs if England can bluff their way into a final and win it.
I can't agree that England are playing to their strengths. They're like a football team that defends and kills the ball, hoping they can take it on penalties... or a boxer who defends for 15 rounds and wins on points. At least in 1991 their pack was aggressive.
In both games, Australia and France made mistakes... a ton of mistakes... England's counter rucking was awesome against the Aussies, but France were clueless against England in the semi. England were well organised defensively, as I said, but tenacious is something you don't need to be when France are kicking into your dead goal area time and time again.
Anyway, South Africa play the same as England -- feeding off mistakes. They just have an injection of pace in their backline. England can win if they dictate the pace. South Africa sets the pace through their rush defence, but England won't try to take that defence head on & probably won't cough up intercept passes.