"And then the status quo took root & reusable rocket proponens were no longer taken seriously because - what were they thinkig, this is how we have always been doing it!"

Disagree as someone who as a kid watched this happen in real time. The Saturn V follow on was always planed to be reusable, with a huge first stage booster that was something of a bigger brother of the stage that would make it to orbit. NASA was starved for capital after Apollo and this resulted in the horribly deadly and very expensive to operate kludge of the eventual Space Shuttle.