That's the thing; while it is discriminatory, it has been (and can be) used for subjectively good reasons, like Wikipedia Zero.

There are many who argue that zero rating is not a part of net neutrality and should be allowed. That's what I meant by saying that it's on both sides. I personally have mixed views, mostly leaning on the zero-rating-is-bad side, though I do feel that it may be possible to come up with a way to restrict what is allowed that helps boost accessibility of internet resources like Wikipedia without giving a competition boost.

Anyway, my point wasn't to argue for or against zero rating. I merely wanted to point out that zero rating was not objectively a part of the net neutrality debate.