But the idea/premise of a highway is to move stuff (people, drugs in your trunk) from one location to another one.

The idea/premise of a private frequency band is to move data (voice, binary,..) from one point to another (or many).

The idea/premise of ham radio is to learn and experiment, to test your devices, compare with others, see how far your signal reaches, etc. It was never meant to be a means for private 1-on-1 conversations.

How will i test my receiver if your transmission is encrypted? What will I learn from that? How do I know that you're not abusing the bands for commercial use? And what do other ham radio operators gain from you transmitting encrypted data?

Who cares? Really, what is the big deal? Nobody is saying that it will always be encrypted. Other radio operators gain the ability to learn about encryption! And we expand the hobby, which as a new member is dying. The radio waves are dead. Why?