"The biggest organisation we needed to join 6UK was the government" the former director, Philip Sheldrake, is quoted as saying. Without government support "There's no material incentive for any organisation to go for IPv6". Government interest can be gauged by the fact that no government website currently sat on an IPv6 address.
The UK is among the nations that have done the least to move to IPv6, and lags behind other nations in adopting the new protocol. In contrast, governments like that in the US are encouraging adoption of the new protocol by mandating IPv6 compliance in contracts.