A No Peering Policy is a reflection of having no desire to peer.
These companies generally do not see the value in peering and/or focus on their strategic core business. To them, peering may be of value but it is not in their strategic core interests to do so. They may focus on content creation, may get better pricing and performance from outsourcing all network operations, or simplydid the calculations and the cost of peering is more expensive than purchasing transit. As a result, you won't see these folks at Peering Forums; in fact, they most likely to not have a network team at all to send to a Peering Forum.
Peering Policies can be described in these these rough categories:
Definition: An Open Peering Policy is an articulation of an inclination to peer with anyone.
Definition: A Selective Peering Policy is an articulation of an inclination to peer, but with some conditions.
Definition: A Restrictive Peering Policy is an articulation of an inclination not to peer with any more entities.
Definition: A No-Peering Policy is an articulation of an inclination not to peer at all.