Because it's a slow, broken reimplementation of things which Angular already does better and which only work well in any case when you're on a blazing-fast low-latency Internet connection, or better yet browsing localhost -- did I mention those times I posted earlier were on desktop? I shudder to think what'd happen if I tried loading it on my phone.
And it also appears to be implemented entirely in a single 1300-line-long Javascript file, which, okay, I guess? There are no tests -- yes, there are examples in a directory called "tests", but there are no tests, which is to say there's no way to get any confidence that modifications in that 1300-line Javascript blob haven't produced regressions or new bugs.
Presumably the author has learned something in the process of writing it, although I can't imagine what that may be. I don't know why he'd spend his time on this, though; from the looks of his Github account, he's also written an in-browser Pokemon game engine which looks pretty cool, so I don't know what value he sees in hacking up a half-baked me-too web framework.