For political reasons, the government threw billions at ULA to keep them alive even when they know they can't do it, wasting time and taxpayer money on an unproven rocket instead of fully backing the clear winner SpaceX.
They handed the lion's share of the money and missions to ULA's unproven "paper rocket" just to prop up the old guard.
To be fair, the US doesn't want one launch company to have an effective monopoly. ULA was viewed as a (relatively) low risk alternative to Space X. Turned out that was wrong.
There is history behind this. In the mid 1980's, the USAF had two launch systems available - the Space Shuttle and the Titan III. Then both suffered catastrophic failures and were grounded for an extended period - leaving the USAF with no available access to orbit.
They don't want that to happen again.