"... because the agency reasonably determined that a single-award approach is in the government’s best interests for various reasons ..."
could be rewritten in plain Merican-English as
"... we are not a financially corrupt institution and we live in the land of the free, like what His Excellency our Glorious Leader the Hair Monster says, so actually it's all ok because 'reasons'. Please move along and continue to enjoy freedom somewhere else before I set security on you."