Even if Great Britain doesn't win a medal at the Olympics...

I’m not a pessimist and I’m sure that Britain won’t walk away from the Olympic games medal-less but imagine if they did. Would it be that bad? Probably not because the legacy the games are going to leave behind is going to be massive.
London is hosting the games this year which means hundreds of previously unemployed Londoners have been trained and employed to build the Olympic Venues. Hopefully when the games is over they will be able to use the skills they have learnt and get a job or start their own business.
When the Beijing Olympics ended, they turned their Swimming Venue into a massive swimming complex with huge slides and big pools so normal people got an opportunity to use the venues instead of the venues being exclusive for athletes.
Hopefully London will do something along these lines with all of their Venues.