Share-Alike Open, But Not Non-Commercial

Rufus Pollock has a new post arguing that the Share-Alike clause of the Creative Commons license is open, but the non-commercial clause is not. From the post:

To reiterate: it is a mistake to view the set of licenses as some continuous spectrum of ‘openness’ with PD at one end and full rights reserved at the other — with the implication that all licenses in between are more or less open.

David Wiley responds. Steve O’Connor on why he choses CC BY.