Exactly, but the thing is that both Boeing and Airbus know this. They know China will take the technology, make poor reproductions of it, and then eventually make better/as good versions of it. Basically what Japan did with the automobile industry - just at a larger scale. Their dilemma though is they believe they cannot abandon the immediate market opportunity, and thus they will play along until they eventually get hoisted by their own petard
In other words the current C-level execs are willing to sacrifice the company's long term viability for their short term bonuses.