I'm finding this highly principled conversation fascinating to read - I'm genuinely learning a lot about the different arguments (both philosophical and practical) used to support or critique Wikipedia Zero. What a diverse and highly informed group of people this list contains! :-)
From my Australian perspective, it's interesting because we've never had
'net neutrality' in the way that it is described in the US and, with appropriate competition and regulation this is not been a problem. e.g.:
"Net neutrality is an honourable aspiration, but the Australian internet
service provider market has thrived and innovated without it. Discriminatory pricing in the form of unmetered content is more a consumer bonus than an imposition of someone else’s choice. http://theconversation.com/australias-net-neutrality-lesson-for-the-us-22245
While I genuinely support the idealism of the net-neutrality debate, and it makes sense in certain jurisdictional contexts (notably the USA), I am won-over by the arguments that have been made here about how WikipediaZero is non-rivalrous. As Marc P. put it earlier:
So it's clearly neutral in the "equally available" sense of the term. And it remains neutral in the "competition" sense of the term since they are welcome to zero-rate any other service they wish alongside ours. And, finally, it's also neutral from a conflict-of-interest point of view.
When looking at the practical reality of a high-school in a poorer district of South Africa specifically asking for greater access to WP from their local telecom company[1], it's hard to remain stuck on purely-principled debates. That is a *real world* group of of people that is *specifically* asked for easer access to Wikipedia - *of course *we should support that.
This is *not *to discount the importance of principles - and a lot of good ones have been mentioned here - but I'm not going to argue against a school-group in a poorer country wanting "free-access to the sum of human knowledge" on their mobile phones because of a political fight in richer countries about heavy-data usage on high-speed broadband.
-Liam