Aviva is unusual as it voluntary put its CSR report to a shareholder approval vote last year. As an investor this is something Aviva has argued that other companies should do. Whether you agree with this idea or not, and responses to the BIS consultation on narrative reporting suggest that most people aren't yet convinced, I really struggle to see a good argument against companies doing it voluntarily.
Someone, however, disagrees. A not insigficant institutional investor abstained on the vote on the CSR report at Aviva's AGM last year. Not because they disagreed with the content, but because they didn't think it was is shareholders' interest to put CSR reports to the vote.