Valid point.
I recall late 60's when you were only allowed to take something like GBP 20.00 out of UK. Not saying that is correct but with so many unemployed in resort towns people staying in UK would feel they are doing their bit for Britain.
Anyway I agree people should make their own choice but should take all factors into account.
For instance your holiday in ZSA probably included a vastly subsidised air fare ( because air fuel not taxed anything like fuel used in domestic transport ) . Also more green to take a UK Holiday.
I guess with the falling GBP more people will stay here for pure financial reasons.
I agree people should make their OWN choice. But people who take long flights should be wary claiming to be green.