This is ahistoric. No-one ever said we had to "just vote for Obama" to close Guantanamo Bay.
Frankly, Obama _tried_ to close Guantanamo Bay. He significantly shrunk the population of inmates, but it was ultimately Congress, and the courts that prevented the closure
Obama spent a huge amount of time and political capital trying to clean up Bush's messes.
You're supporting the point of the person you responded to.
Obama only tried to close Guantanamo by moving the prisoners to the United States, which is arguably worse than having them in Guantanamo. It would mean that you could hold prisoners in the United States indefinitely without trial. What he should have done was give the prisoners fair trials or release them.