During the 2011 Fiscal Cliff discussions (which lead to the Super Committee), sequestration was part of the comprehensive deal about revenue — but only in a limited way. At that point in the conversation, the conversation was how much to cut spending.
It was Congress’s idea (and Obama went with it) — to use sequestration as a stop-gap. Sequestration’s only purpose was to provide a number and use it to be a placeholder until they determined what exactly would get cut. They were not really going to cut 600B out of the military, but they’d cut here and here and THEN decide where to place major cuts that would total the $600 Billion.