It's also relative. Certainly, a GUI + mouse is closer to intuitive than the command line. The iPad's multitouch is a little closer still. Reactable strikes me as yet closer. (Granted, it's domain is much narrower.)
I don't know... I've always found the command line to be easiest to use. Certainly, it is very far from aesthetic, but very functional. There are no stupid metaphors to deal with, just commands. what do you want to do? then type that command in. it's like math.
You may have a point. All I had at the tender age of 11 was the "]" prompt on my Apple II+. There are abstractions to deal with on the command line, but for the most part, they exist in one's head, so there's no worries about someone else's weird metaphor getting in one's way.
it's like math.
YMMV. Most of the HN population can deal with math. Some people's pupils constrict and their brains shut down.
OK, the computer is organised in terms of files and directories where a file is a chunk of information with a nametag like in an office filing cabinet, and the microphone is presented as an imaginary never ending file where the chunk of information changes every time you look at it, and you'll need to run a program to repeatedly look at the file and copy the contents to a new file in a directory of your choice... no, you can't put it "anywhere" and then search for it later, you are forced to choose a directory for it.
Your files have all the lines messed up? That's because it's built as if it's a typewriter with a forced "I'm at the end of a line" instruction which you never need to care about until you get a page from another typewriter where the operator had to push a different button at the end of a line and when he looks at the page it looks fine but when you look at the page you see it as if you had typed it on your typewriter pressing his end-of-line button which you don't have on your typewriter so it doesn't do anything, so you see one long line, ha ha!
Those are very valid and true criticisms for current command lines and the way they interface to the larger computing environment on which they live (and you didn't even go into all of the problems you could have). But I want to point out the attack has a limited scope in an important way, command lines that have been built in the past, with roots that go quite far back for most of them.
Just as it isn't a full and knock-down criticism of GUI's to point out that people have done them badly, this attack doesn't go to the core idea of command lines, "type what you want to have happen." The available metaphors can and should be made more in line with how people think of what computers can do.
What command lines are extremely lacking in is not "intuitiveness". For anyone who is passably literate (or maybe even just anyone who can speak), using words to say what they want is quite intuitive (in the "familiar" sense, which seems to be what UI discussions fall back to as a working definition for "intuitive"). No, what command lines lack, in most (if not all) current implementations is discoverability to the vocabulary and grammar, some friendly feedback, the forgiving-ness that new users need to get past that fear of doing the wrong thing, and hand-holding teaching-the-steps-toward-complexity kinds of things (if complexity is wanted by the user).
Someone in another thread mentioned that their parents have trouble with even the abstraction of programs for tasks. The parents know what they want to have happen "send an email to their son", but connecting that to a program that needs to be started and used and then possibly closed again is something they seem to forget. Well, in that case, a simple command line environment for getting them to the right task-based interface would be as good as anything else, so long as it had a natural and discoverable vocabulary. It is perfectly natural for me to put some words in a row to communicate to you what they wanted, and at some point they probably put some words in a row to tell him what they were getting frustrated with the computer about. So why is it that one would think that having them put the same words in a row for the computer is somehow, despite being quite intuitive in all these other contexts, suddenly for the computer it is not intuitive?
No, back in the day computers simply weren't up to the task of interpreting all the myriad ways that someone might have said "email my son". And command line environments were not made with discoverablity, friendliness, and forgiveness in mind. The people using them were willing to bend their own minds to the limitations and peculiarities of the command lines. And instead of making them better and better for other users, the programmers and designers thought they could get more bang for the buck with pictures instead. Thus things have gone quite far down that path until we are arguing over what visual cues for controlling stacks of windows of disparate interface paradigms are more intuitive, what icon best reminds people of "email", and how to get them to notice/remember which text box they should put their son's name in. Meanwhile computers are quite powerful enough for someone to take an fresh, intelligent stab at merging a command line back onto the screen so that computers can finally catch up to taking commands the way a normal three year old finds perfectly intuitive.