Here are some facts that we do know:
1) He's recently logged into the admin interface of this website
2) Hosting is still online (assuming he didn't prepay for a year)
Like I stated previously, know matter why he is not communicating, it does not set a good precedent for his brand or product. Despite whether or not he is a great programmer with an awesome imagination, no one person should leave it to themselves to do everything. And, he should acknowledge that by him taking on this entire project alone, it will inevitably suffer. From PR to marketing, support and QA - one person cannot and should not take on the entire burden of a task such as this.
So, with us understanding that he did not have the foresight or assuming that he could not get his ego out of the way, and looking at the most recent lack of communication with his backers and fan-base; we can all reasonably acknowledge that he lacks some fundamental skills in PR, management and foresight. It would be one thing if he backed this entire project from his own funds, then we could say that he owes none of us anything, however, as we all know he did launch a Kickstarter fund and accepted funds from backers.
Let us assume that he was out of funds, and that he hit a wall. Even if that were the case he could have always reached out to someone online (in this community or someone that he knows) to help him. Which makes me think that the biggest issue with him and his mindset is that he is too attached to LT. Let us take an excerpt from Josh's last post on this forum:
Maybe Januray 2013 or so
I wake up each day with a vision of an infinite, procedural universe in my head, I go to bed with it, I live, eat, and breath Limit Theory right now. I have to make a concerted mental effort to remember to eat two meals a day, I nearly loose control of my bladder each time I need to use the bathroom, because just one more minute with my work will be worth that pain
I've got a plan that's getting clearer every day, I've got a dream with which I'm falling back in love more and more each week, I've got an excitement that's setting me on fire more and more and more, and I've got a toolset that turns more and more miles into an inch each month. For once -- perhaps in the entire development process of LT -- I feel that I am living up to what you all expect of me. What a feeling. But more than that, it is the feeling that my dream is really, actually coming to life with alarming speed, right here on my screen. And that yes, it can actually be everything I wanted it to be.
Living and breathing your project to the point of foregoing all others aspects of your life does not seem healthy, and it kind of feels like he is (as I mentioned before) too deep into this game; to the point where maybe I don't know... maybe he's lost touch with the goal of this project. It's tough to say because his last video update made it seem like he was mentally all together, but from his own words he tells the tail of being so immersed in this word that he's created, I don't think it's that far of a stretch to say that he may have lost touch with reality.
The forums are still going, but for some reason he makes 0 effort (even though he knows that everyone is wondering where he is) to reach out. He knows but for some reason he... makes the conscious effort to continue and harm his brand and upset his fans and backers. It just doesn't make sense to me, I'm sorry. It's too strange.