If my half of post 129 was viewed in a vacuum, then you'd be correct in your concerns. But, the context of my answer to MwRYum's post is while the C-919 didn't meet the goal of producing the aircraft from an entirely home-base production chain (thus the failure), it was nevertheless a step in the right direction.
Ok, so MwRYum's key goal is the final ultimate goal, not the first step. Note, I don't use his word "entire" as most of us know that is not possible nor profitable to do, and I believe MwRYum himself did not really mean it if I am right about him. In this sense, he was talking about the final step, while you were talking about the first step. You two were focusing on two aspects, two ends of the same chain.
I am afraid using the word "failure" only makes yourself more than likely being understood the opposite way than you intended to because you and MyRYum are addressing different points of the project. So I still think an alternative expression will probably serve your purpose better.
BTW, it is from this, I had the sense that "both sides have valid points" only different angles. Hope this answer your previous question in #152