When I look at it from his point of view, I feel quite sorry for him. The language's forum has 9 posts in the last calendar year. 4 of those are him solving a problem using Leaf. Then, I check out the status page and realize that, for all the work he has done, Leaf is still in a very primitive state.
I'd equate it to being like a startup. At some point, it stops making sense. Then, you can either ride the ship down into the depths, or hop out when the going is as good as it will get.
As for his dependability, I've got to tell you that, from my perspective, anyone who can pull this off is more than impressive enough.
I think he should be awfully impressed with what he did. And, I don't think it's even remotely fair to judge him as being undependable. Based on what I've seen, I think he should have pulled the plug last year, when he first wanted to quit.