AT&T does not treat all customers equally.
Eligibility is based on many factors.
How many lines you have, service levels, FAN accounts, how long you've been a customer, payment history, the list goes on.
So trying to compare one person's eligibility to another is pointless.
I've been an AT&T/Cingular/AT&T customer for many years. I have a FAN account and am on a family plan with bundled services.
I have been eligible to upgrade after 12 months, regardless of the phone I pick, for several years now.
Not bragging, just putting it out there as yet another example of how AT&T decides your upgrade status.
Loyalty holds a lot of weight in AT&T's eyes. Occasionally they need to be reminded of that fact, but overall my experience with them has been very good.
Getting all indignant about not being treated equally is pointless.