I think any exclusivity "anymore" is a bad idea. The iPhone was a first of its kind.
Now? Cell phones, to me, are basically just all the same.
I don't see any reason for millions of people to jump ship and head to AT&T just because they can get a phone that will let them stream AIV and make it tiny bit easier to buy stuff on Amazon.
No, I agree with you on the exclusivity as a principle but it has a practical reality.
Verizon had an exclusive on the the GNex in the US for a little while.
If I were introducing a new phone, I'd start with AT&T exclusivity - for a time - because the 3G version of that is compatible with most all of the rest of the world, where AT&T exclusives aren't a factor anyway.
Also, same play made with the original iPhone - and a number of others overseas without bothering with the AT&T exclusive - make money on the common denominator model to fund build-out of the other variants.
I think that my beef is that the AT&T exclusive is a symptom - the whole launch was not really thought out.
By my example, the AT&T exclusive model makes sense - if this were the market from years ago.
But it's not, and there's a sign at the bottom of the stairs where new phone makers have to pass on the way up, and it's said this for a long time now:
"You must be *this tall* to ride."
Too cheap to use the tremendous corporate war-chest to explain the product during prerelease, too short sighted to insist that the term 3D stayed out of it (it's head tracking, not 3D), and oblivious to the specs war (it's not a lean, mean Moto X, it's a new level in software).
With those issues, would it have mattered if it hit on all carriers at once? I'm not so sure.