It's a simple question; it's your project, written in Rails. Who owns it?
David Heinemeier Hansson, that's who.
Well, him, the core Rails team, and "hundreds of open-source contributors". And you own a bit of it too …
This has nothing to do with the license of Rails, and everything to do with copyright law. The GNU Project has already addressed this; the GNU FAQ has a couple of sections about the problem, especially in the context of Bison.
''Some programs copy parts of themselves into the output for technical reasons … the copied text in the output is covered by the same license that covers it in the source code. Meanwhile, the part of the output which is derived from the program's input inherits the copyright status of the input.''
This implies that all the Rails code in your application that has been created with the rails and script/generate command is not yours. It only becomes yours after you have modified enough of it to claim copyright ownership – I don't know if this is ≥50% or ≥75% or what … and I'm sure your local jurisdiction will have an opinion.
I started a thread about this on the Rails mailing list – have a look at the forum bridge for the current situation.
However, don't panic – it's clear that the intention of all these authors is that you should be able to use their code for your own work. This whole situation seems to be a minor bug … explicit comments in the various README or license files should be enough to clear it up. But in the meantime …
All your code are belong to us …
Another old paper (and extracted from the middle of a slashdot discussion), but it seems to be well worth reading. People are the factor that causes software projects to succeed or fail, not methodologies.
Problem 1. The people on the projects were not interested in learning our system.
Problem 2. They were successfully able to ignore us, and were still delivering software, anyway
So, rush off and read Characterizing People as Non-Linear, First-Order Components in Software Development