I disagree. If someone is starting Ruby for the first time, the last thing they want is to be forced to learn another new language on top of learning Ruby. Then mix in Sass and Haml, and you're giving them a good reason not to even bother.
This change definitely has the existing Rails community in mind.
Or as I told my friend: "Given that you already know how to create a blog in 5 seconds, how can we also make you not have to use semicolons in your JS?"
So it's your first web page, eh? Do you know HTML? No? Do you know CSS and JavaScript? No? Okay, the first step is to figure out how CPanel and PuTTY work ... what? What do you mean Microsoft Word isn't a real text editor? I edited my whole thesis on it. IDE? Isn't that like a hard drive? WTF?