I might be a little sarcastic here but let's face it: sustainability is the no.1 buzzword of the past decade...
Companies see sustainability as an investment. Not so much for environmental reasons but for the sake of marketing. The (quasi)sustainability of the company, their products and of course their buildings has to be noticed by the public at all cost. Therefore it needs to be visible. Perhaps it should even be screaming and obtrusive.
What's your philanthropic-weapon: a windturbine-on-the-roof? a solarpanel-parkinglot? a green-facade?
Sustainability is a marketing tool. (as is Santa Claus)
The most beautifull part of it is the fact that the public is buying it.
Ah well... "...ignorance is bliss..."