An investor trusting her savings to a fund manager, or an insurance company, has probably been attracted by the win-win narrative emerging from the data thus far (sustainable investing is good for the planet as well as for the investor’s wallet), but might well change her investment choices if conditions changed. In that case, the intermediary would have to follow its client’s guidelines.
Furthermore, whereas many investors express a demand for sustainable assets, others do not; intermediaries featuring both investor types among their clients can hardly make pledges on behalf of the latter.