ULA (a largely anticompetitive merger of Boeing and Lockheed for those who don't know) was actively and patronizingly taunting SpaceX during their efforts at reuse, making comments along the lines of 'We tried reuse. The economics just don't work out. Good luck learning what we already did.' He (Tory Bruno, CEO of ULA) seemed to be under the impression that reuse was only possible Space Shuttle style, which was them essentially "refurbishing" engines to the point of rebuilding them after each launch, and claiming it was reuse.

There's every reason to believe that this is also exactly what they genuinely believed - that SpaceX was just going to be a failed gimmick. They made 0 efforts to try to ensure they stayed technologically ahead of SpaceX, in spite of having many orders of magnitude greater resources and manpower available to themselves. They simply watched, mocked, and became obsolete.

In any case ULA's not going anywhere. Boeing and Lockheed are both major arms dealers that the US government depends on to keep the bombs flying.