I didn't say that. It was said to me by a prosecutor of those who use tax haven services in furtherance of corrupt activities whilst I was in Norway last week.
Mind you, I agree with him: there is nothing we could think of that can be done in a tax haven that could not be done legitimately onshore. In which case the world does not need them.
Given the harm they cause it's easy to see how this person came to his conclusion. And it's one with which I find it easy to agree.