While I agree that the iPhone shouldn't be tied down to one carrier in any particular area, I don't believe that the UAE has any justification for prohibiting such an agreement.
Judging from the article and the comments following, it appears that the UAE is not thinking clearly in regards to this issue. Assuming that the facts presented on that page are correct, it seems as if the UAE is playing favorites in regards to devices, and their telecom regulator simply wants to complicate things.
Now, I'm not too familiar with the dealings of the UAE, but judging by the article, it does seem unfair for this to happen.