I guess the difference is that Gnash guys hate Flash with passion, whereas Miguel & friends recommend the technology they work with as reasonable choice for new development.
So, Gnash is OK because the developers hate Flash because it's proprietary to Adobe? This whole thing is truly laughable. I don't see how reverse engineering a platform from an openly published API spec is any different to reverse engineering an operating system by reading and understanding its source code. Maybe Stallman really did hate UNIX after all.