The huge advantage to this approach is that it makes it impossible to create syntactically invalid constructs in the language. A text based interface is hard to beat for simple speed of data entry... With lots of practice, people can type significant words per minute, and what you learn doing it in one language is completely transferable to every other text-based language. But when you consider the fact that the space of possible strings is so much larger than the space of syntactically valid programs, one does have to wonder how much time we burn on avoidable syntax errors. And nothing is stopping anyone from applying a keyboard to this programming approach... Somebody just has to sit down and figure out what that would look like.

What if the tools made it nearly impossible to write syntactically invalid code and were coupled with the discoverability to figure out what is valid in any given hole in the construct? Blocky isn't there yet, but it's an interesting foundation someone could build on.