Include a javascript runtime when generate the app

Hello, I'm opening this thread in order to discuss a frustration that I have since Rails 3.1

I am teacher in private courses and university in Brazil and my main language is Ruby (along with Rails for web classes). I have more than a thousand students and I'm starting to know very well which part of Rails and Ruby are hard to explain for beginners.

A lot of people said that Rails is getting less friendly for beginners but that's not true and I can assure that it's not true in most of the points except for one:

"Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)"

In last two or three month I trainned more than a hundred new students and answered at least 10 times why they need to install a Javascript Runtime for a tool that's based in Ruby. Most of people don't even now that you can run Javascript outside the browsers, and if you can, what are the benefits.

I really advocate first class front-development and I love the additions of Rails 3.1 but we need to make it easier to start.

Not everybody is using OSX and require people to install nodejs or manually open the Gemfile to add therubyracer it's not a good solution (specially when I present Rails as webdevelopment without pain).

So, I would like to raise the discussion about this issue:

Maybe the Gemfile is not the right place for the checking. Probably we could move it to ExecJS?