If the plane crossed the Maldives and then headed north Iran could have been the destination just as easily as Pakistan, couldn’t it?
My guess is if the plane landed in Iran the Iranians would blow it up or call in the UN or something. They don't want the finger of responsibility pointed at them. Same with Saudi Arabia and many of the other States over there... they don't want it.
Remember Osama bin Laden lived a few miles from a major military base... And we're told no one knew? Those folks know how to keep a secret... "Oh, THAT Osama? We thought you meant a different Osama..."