Most forms of utility, including forms that come from using a CLI, have an acquisition cost. Rationally it makes sense to invest in things whose acquisition cost is lower than their utility. When a time horizon is introduced, for example, five minutes, the rational response changes. The acquisition cost becomes higher than the value generated. Once you've learned something there is no acquisition cost. So generalizing from that position produces the prediction that others are behaving irrationally. Which they would be, if their bandwidth was unlimited, but in practice they have to spend more time doing real time work because they live in a time context and only have a limited budget on which they can spend non-realtime thinking. Since there are a whole host of different things which have lower acquisition costs than expected utilities, some people end up exploring, say, genetics or rocket science, instead of computer interface usage optimizations. They weren't being irrational. They were constrained and they made the cooperative choice to let you explore one thing while they explored another. As a result, you can learn from them and they learn from you and the overall acquisitions costs for everyone are lowered.
Another way to say this is that the people who were too intimidated to use CLIs know things that you don't that are of the same character as your own knowledge of CLIs and it shouldn't have been overly complicated for you to know those in a modern society seeing as you are literate.
If you think people should really do what you are advocating: pave the roads. Lower the acquisition cost. Make it easier for people who are time constrained to do the thing you think they should be doing.
And so people did... and now we arrive at why things are the way they are.
It turns out that in the case of CLIs there is a usability problem. CLIs are constrained to text. Other mediums are a superset. They have more options for lowering the barrier. The people who are doing the paving in those cases are able to make better progress and faster! The masses flow to the GUI, not the CLI, because the GUI does a better job lowering the acquisition cost! It is a fight. On one hand we have the CLI, a hand tied behind its back. It is not allowed to go beyond text. In the other we have the other mediums. They have text, but are not limited to it. Should the CLI overcome them, they shall just put a little window wherein the CLI is present. They might do a nasty trick when they do this, stealing the fame of the CLI, by calling this a TextArea or a TextInput or even a TextBox.
Woe to the CLI, we type into the textboxes, supposing that the GUI has won.