There are reasons for that attitude. Off the top of my head....
- NASA way, way, way oversold the shuttle in terms of cost and turnaround time. When you can only launch three or four times a year, you can't replace -any- of the other heavy lift programs.
- The results of the Challenger and Columbia investigations which showed poor decision making at NASA. "My God, Thiokol, when do you want to launch, next April?"
- The endless series of Shuttle replacement programs that never got off the drawing board. I tell folks that all the shuttle replacements are stored in the back of that government warehouse right behind the Ark of the Covenant (last scene of "Raiders") along with all the Middle East peace plans.
- the Ares/Constellation program, which carried with it the strong odor of pork (ensuring many more decades of gravy for United Space and Thiokol)