Have you ever read the history of shuttle development? Nasa got little of what they asked for and ultimately built the vehicle the air force wanted.
In no other area of transportation are expendable vehicles considered viable. They were only used for launchers because it was easier to use the ammunition that was available than developing a new system from scratch.
From the beginning, von Braun and others envisioned reusable vehicles and planned to develop them at the first opportunity.
Congress cut NASA’s budget. NASA’s response should have been to dump the plans for a quasi-reusable vehicle, but of course it didn’t, it pushed even harder for it, and dumped every other proposed project. The Air Force wasn’t interested in it without an increase in payload capacity, which meant a larger vehicle, which meant SRBs.
The interesting thing about the SRBs, which are often complained about by, well, idiots, is that they are reusable components, and in terms of bang for the buck, they actually make the most sense. In the upcoming SLS enhanced versions will make their return to man-rated vehicles.
As disposables.
Four of the existing-design SRBs could send a manned lunar mission into direct ascent trajectory to the Moon — no shuttle, no liquid fuel first stage engines, just light and go. That could be designed in a couple of years, and launched to the Moon by 2020. A single SRB costs about $50 million new, the estimated cost of recycling that I’ve seen is $18 million per SRB per launch. IOW, even if the four-segment SRBs used on the Shuttle were put together for a lunar mission, and thrown away, it would only run about $200 million for the first stage; if recovered, the cost for subsequent missions would drop below $60 million for the first stage.
Von Braun never worried about reusability, he understood the tyranny of the mass budget. He wanted to use the Saturn V boosters to assemble Mars missions in orbit. His vision would have led to twelve Saturn V launches to assemble a single manned mission to Mars.