Just some random thoughts about this, but first a minor rant. I disagree with the basic premise that computers now lack any 'direct interface' to creating computer programs. Every OS ships with at least a basic text editor, and good free ones are readily available. That and a browser are already a better programming environment than I had on the Commodore PET in my high school's chemistry lab.
On that computer, writing BASIC programs was pretty much the coolest thing you could do, and just about the only thing. What's different now is that there are a _whole lot_ of cool things you can do with a computer. Kids are using them creatively for photography and movie making, art and design, communication, music, and of course games. The cheesiest online flash games are way more exciting than all but the very best old time BASIC games I could write and play. So while the programming environment has generally improved, it's obscured by an avalanche of additional functionality that computers now have.
So why can't Johnny code? We had three Commodore PETs in our chemistry lab, and J.B. was always sitting in front of one of them. But it was hardly ever a problem finding an open one after school. Most people just aren't that interested in programming. Back then those people just left the computers alone. Now they've got them for other things, but they still aren't interested in programming and that's fine. You could just as easily ask why more people aren't growing their own food or carving their own gunstocks. Life is short and everyone has to make decisions about what to do with it.
If anything there are more people involved in coding than there were 20 or 30 years ago. All you need is a few dollars a month for a hosting account and a Wordpress theme to be a web design firm. There are probably thousands - millions - of people doing that very thing. And little by little, some of them are being drawn deeper and deeper into the code.
The opportunities for teaching kids programming are better than ever. Kids have ready access to computers and are already familiar with their basic functions. The internet is a source of inspiration, a resource for learning, and an incredible opportunity for self-publishing. HTML and CSS are easy to learn. A kid can make a pretty cool web page from scratch in a short time with very little instruction and see immediate results in a browser even without a web host. If they could just add a little JS action, now that would be shiny!
The main things that make BASIC (and Python) simple and accessible seem to be *natural language* and a certain *linear logic*. It's easy to call a function in BASIC. You just
`GOTO 550` and
`RETURN`. You don't even need to think of it as a function. You just go there, do that, return.
One thing I think is important to keep in mind is kids' expectations of what a computer program does. When I was first learning BASIC, it was pretty exciting just to be able to make my name repeat and fill up the screen. (OK, at least the first time.) But my kids are accustomed to 3-D graphics, realistic physics, immersive U-I, surround sound, rich and dynamic websites.… They judge the success or failure of what they create by the standard that's available to them in the real world. So hopefully you'll be able to give them the tools to achieve something that lives up to their expectations.
You're probably aware of the Scratch project (http://scratch.mit.edu/). It's sort of like the Lego bricks of programming. It's a fun way for kids to get started and have immediate success in programming. It's not a Camen Design style project by any means, but it might be helpful to you in researching the set of straightforward functions to include in your language, as well as understanding the educational underpinnings of a beginning programming language for kids.
It won't be easy, especially to do it well. But helping to expose the creative power of the browser without burying it under a proprietary, pre-packaged interface is a worthwhile project and I hope this idea will continue to grow.