I never said that it wasn't actually open source. I just said that the openness hasn't actually created meaningful competition, because there is a single company in control of the specs that abuses that control to create a moat.
For a concrete example, the bitmanip extensions (which provide significant increases in MIPS/MHz) were used by SiFive in commercial cores before ratification and finalization. No other company could do that because SiFive employees could just change the spec if they did. They're doing the same thing with vector/SIMD instructions now to support their machine learning ambitions.
