Robert Tiltons application is almost everything Musk seems to have done, except the lack of interfacing with CAD software (for example gesture based modification).
The other 2 links are, whilst only tangentially related, really cool, so I thought I'd post them as well.
So really, the question isn't "Why didn't it exist yet?" it's "Why was Elon's system featured on thenextweb, and Roberts wasn't?"
