<anecdote>
Ruby is going the way of Java and for the same reasons. Rails originally made easy things easy and hard things possible. Now, for novices, easy things are harder. Java went the same route largely as a result of the debacle know as J2EE.
Java suffered the problems that it did because there was the "one true way" of J2EE until Spring eventually came along and made it (marginally) better.
Merb provided that for Rails. Now there's no more Merb.
</anecdote>
The point: we, the Ruby community, are suffering our own success. Popularity leads to people leads to bureaucracy leads to mediocrity. See "JSF".
As a result, this "fork" makes sense to me. Unfortunately, it's just a drop in the bucket. Ruby.next is coming and it's called Javascript (by way of Node) and Clojure (by way of those Rubyists who are LISP obsessed and still use Java).