I seem to have heard this theory before........why fight a war abroad that doesn't concern us?........Funny........we would all be speaking German if that attitude had prevailed.
The Olympics would be a great financial and prestigious event for Britain to stage. If you don't believe me ,go get out the financial records,and Industrial output figures of when England held the World Cup here in 66, and that wasn't all down to the fact we won it either!
Err, what's that got to do with the Olympics? And what's it got to do my point that the electorate of the city certain to run up huge debts and suffer enormous congestion should be consulted to see if they want it to happen?
I presume your point refers to World War 2. The argument at the time was that it did concern us, of course. Whether we would all be speaking German as outr first lkangauge had we lost is a matter for speculation. We don't speak Norman French and we don't speak Latin. We do however speak a descendant of Early English, which is itself an, errr, Germanic language! So in a way we are already speaking German.
Now that has got absolutely nothing to do with the Olympics, I grant you.
There would probably be a serious effect on the construction industry as labour and materials would be gobbled up the olympic city thing, hence forcing prices sky high elsewhere - if you could get them at all. There would no doubt be an influx of European labour. Certainly industry would benefit, not only construction but all the spin-off industries, during the construction period, but it's not easy to see how these benefits would be sustained.
As for the tube lines, a new tube line would be hugely expensive. What we need is four more Circle Lines!