To be honest you're just arguing semantics as Blink is a fork of the same webkit components that Chrome was using previously. So little has changed from a rendering perspective.
Given the amount of redundant code in webkit due to Google and Apple pushing the library in slightly different directions, it does make some sense to fork it. And it's really no different to Apple forking webkit themselves (webkit2).
However when the forks diverge more in the future, your point will be more relevant (just as the difference between kHTML and webkit is now quite pronounced).
In any case, I did reference Blink in my first post. So your point isn't lost on me :)