Your argument that free software must be independently re-implementable, under other, less restrictive licences, doesn't seem like something that'd be universally agreed on. That would imply that when patent grants were added to GPLv3 which extend ONLY to downstream recipients of the software (i.e. NOT to the implementation generally) that they created a non-free licence, or at least less-than-free.
I'd agree that the Java language specification is less than free. It's clearly patent encumbered. However, I find it hard to agree with how you then try to paint OpenJDK as being non-free.