Curious about the transition from Apollo to the Shuttle

With regards to the guest on the space show, a Mr.Muncy- my thoughts a) there exists heavy lift mindset, whose proponents believe that only a heavy lift rocket can enable significant missions b) he spoke of a frontier spirit as fragile, but necessary, or society will turn inward.

This made me curious about why the Shuttle program was adopted, as opposed to continuing with the Saturn rockets.  A nuclear capable Saturn could launch more than twice the payload of the conventional Saturn rocket.  Given that heavy lift mindset, it is curious to me why the Shuttle was adopted.

I am coming around to the opinion that heavy lift is only needed for specialized missions.  You need to get stuff up there and a big rocket is necessary for those missions that need specialized equipment.  However, it should not be used for all missions.  Smaller rockets can get people up there, as well as limited amount of supplies.  Basically, you get people and routine supplies up there frequently on smaller rockets, and use the big rockets to get big payloads that can't go on smaller rockets.

Could it be that the Shuttle had too many requirements?  Was the Shuttle the right way to go after Apollo?  What were the options?  What could have been different?  Are there any lessons to learn from this?

There are those who are against heavy lift as well.  But how do you get big stuff up there without it?  Constellation was cancelled along with the heavy lifter that was planned for it.  Now, the government is funding a new heavy lifter.  But it is not clear what the mission is for it.

The fragility is with respect to a poll that Dr. Space mentioned.  People seem to evenly divided on the purpose of the human space program.  Nearly half don't think there should be one, if that interpretation is correct.  More failures only compound the fragility.  People may consider it to be too dangerous and expensive.  This is a problem, because it could lead to the end of human space flight.

Having the government produce a heavy lift rocket is likely to fail.  There are already smaller rockets, but these are not man rated.  Clearly, the alternative of using smaller rockets with fuel depots can be considered in lieu of a heavy lifter.