do you seriously think his citizenship status is all we care about?
No, but that is all that is relevant to his eligibility.
Since the argument is that he needs to release various documents to prove that he is Constitutionally eligible for the Presidency, what else could be at issue? The only other qualifications are age and U.S. residency.
And I presume no one is asking Obama to prove that he is over 35 and has lived in the U.S. for over 14 years. Citizenship status is all that's left.