Why does work need play?

Lego's "Serious Play" people ask a serious question about the relevance of play to work. Here's their even more serious answer:

Play helps release thoughts that are locked in the head and the heart.

You see things differently. Ideas come to life with more concrete detail than ideas expressed through just talking.

Discussion during play happens on a more level playing field.

The group at play thrives only when everybody participates, so frustrations are reduced, team coherence and direction is more solid.

Play lets you experiment, explore and take risks with ideas without fearing consequences that might happen in "real life."

You generate a wider and more imaginative range of possibilities during play than you would during a traditional business meeting.

People at play are more present, more engaged, more passionate and better performers.

I'd like to propose that these observations about the relevance of play to work be taken beyond the wonders of Lego and the rarified atmosphere of the creative team. I'd like to see us take play at work so seriously that we accept it as essential to the health of the workplace. In fact, I'd like to see these observations about the power of play be taken everywhere: to the workers, clients, vendors, and especially to family and community, school and club, hospital and retirement center. Seriously.