This seems a bit one-sided. What Joyent has been doing is called "maintaining production software." That's something I've been missing in the web world lately. It's surprisingly hard to find high quality libraries that don't change all the time (that is, break all the time). Libraries like jQuery, normalize.css, and Lodash are the exception here. They're some of the few libraries that I'm comfortable guessing will look pretty much the same they do now a year from now.
That is not to say that I don't want to write my gulpfiles in ES6 as much as everybody else, but you have to understand that this whole forking thing scares off people who are looking for a platform they can invest significant time and money into (that is, write more than a million lines of code for).
With that much change in such a short time, it would be extremely optimistic to think something didnt break. If I had a lot of production code depending on node, those numbers would scare the crap out of me.
You can absolutely migrate angular 1 to angular 2. Following good practices (i.e not having 4k line controllers) that were place since its inception only makes that migration easier.
Node.js 0.10.0 was released on March 11, 2013. 0.12.0 was released almost 2 years later on Feb 6, 2015. By all accounts 0.12 isn't even a major change over 0.10.
The io.js team has done more in a few months than Joyent did in 2 years.
I, personally, don't care if node.js and io.js ever merge. One is clearly a superior product with a superior open source governance model.