The practical limitations all make sense. It's not like there was really an option, but the development of deep throttling engines and reusable boosters was definitely not helped by the majority of funding going to getting spy satellites in orbit and ICBM development.

If the goal really was actually space exploration and not warfare/spycraft, we would have likely had some form of reusable rocket way sooner. We just had all these excess rockets laying around that were meant to carry a 2000lb warhead that could also carry 2000lbs worth of dudes.