Why do people support tax havens?

I was disappointed to read this:

Renaissance Group, one of the world’s leading high-opportunity emerging market financial groups, today announced the appointment of Dr. Ngozi Okonjo-Iweala as Chairperson of its African and Nigerian Advisory Boards.

Renaissance claims it is:

an independent group of investment banking, asset management, merchant banking and consumer finance companies, specializing in high-opportunity emerging markets. Renaissance Group operates in Russia, Ukraine, Kazakhstan, the United Kingdom, the United States of America, Cyprus, Sub-Saharan Africa, the British Virgin Islands, Switzerland and Bermuda.

Or to put it another way, this is a group committed to promoting tax haven activity.

Dr. Ngozi Okonjo-Iweala is a former finance minister of Nigeria (the best they’ve had), a founder of Transparency International and someone who is seen to have stood up against corruption.

So why join a group that supports tax havens? I’d love to know the answer.