There you go. He thinks his carrier is Apple's customer. Thus the conflict, because Apple treats iPhone owners as its customers.
As Gruber would have it, the tension between phone carriers and Apple is over whether the carrier or the customer should have control over the device in that customer's pocket. That is disingenuous.
Here's the real bone of contention: Telstra believes Telstra should control what you can do with your iPhone. Apple believes Apple should control what you can do with your iPhone.
You'll notice the customer doesn't get the final word in either vision. Gruber doesn't care because he happens to think (like a hell of a lot of satisfied customers) that Apple's walled garden is particularly nice.
There's a very straightforward litmus test here: when Apple stops actively seeking to prevent iPhone users installing software other than via the iTunes Store, on that day they can be said to be putting the customer's interests first. Not before.
All timestamps are Melbourne time.