A number of points jumped out at me.
In the absence of real-world examples, the wishful thinking of armchair designers leads to a "grass is always greener" mentality: *every* alternative must be better than what has been tried already, because we know all too well the disadvantages of what we have tried, but of the road not taken, we can see only the advantages.
That brings me to mind the reoccurring kerfuffle over NASA's chosen method to return to the Moon. Every disadvantage of the Ares boosters are highlighted (and at times exaggerated) and every advantage of whatever chosen alternative is being discussed is touted.
Jorge Frank goes on to suggest a road not taken:
The alternative - the real "road not taken" - would have been to build small experimental vehicles, starting from suborbital and working our way up, that explore all the different "corners" of the design trade space resulting from this multi-variable problem, and learning, one painful step at a time, what works and what doesn't. Since these experimental vehicles would neither have carried payloads nor flown operational missions, there would be no attachment to them; they would have flown for a few years each and then retired and replaced with the next X-vehicle, just as happened with all the previous X-vehicles up to and including the X-15.
Very sound engineering practice and likely something that would have been very difficult to finess politically in 1972. The demand put on NASA by the Nixon Administration was not to indulge in technology R&D that would one day in the future maybe result in a family of operational vehicles. The mandate was to come up with the solution to cheap access to space. Do it as soon as possible and, by the way, with half the budget you want. NASA was to so this thing or cease to be.
It is fortunate that the dynamic of space politics is not quite so on the edge thirty five years later. There are now a number of small companies trying out different approaches, some of which presumably will fly in the fullness of time. Meanwhile NASA can stick to exploration and science and let the private sector do the job it was meant to.