Sure, programmable by what today we'd call "programmers" but certainly not by "users." This is because programming has become a niche trade (as I said before, like a scribal culture).

I'll give an example. Most users' experience with their host Operating System involves prodigious use of buttons. They know how buttons work and they know how to interact with them. But in all these OSes it is extremely difficult for a user to make a button that does something they want, then, say, place it on their desktop for future use.

In the past there were really good attempts at authorship in computing media (which is more like what the LRG was going for with Smalltalk etc), including Hypercard. In the latter system, you could pop open a button and see how it worked in a comprehensible scripting language. You could copy the button and paste it somewhere else. You cannot do any of this with buttons in the major OSes. The capability is not there.*

The only option available to "users" is to learn a full fledged, general purpose programming language with all the pitfalls that entails, which means learning build systems and all the rest. At that point they have to become what today we call a "programmer," ie a scribal-programmer.

Our dominant systems have been explicitly designed for a strict delineation between scribal-programmers and consumer-users. That's the rub.

* - AppleScript is a so-so attempt at this, but even that has been allowed to die on the vine.