Because there are different tier of engines. The Chinese effort has mainly gone into large (WS-15/WS-10), medium thrust engines (WS-19, WS-13), and turboshaft engines (WZ-10, WZ-16). As a result, they are missing a low thrust class engine, which is where the AI-222 comes in.
Ukraine is only optimal for very low (AI-222) or very high (D-18T) turbofan engines. There is nothing in the middle Ukraine can offer at all ... but on the brightside the engines they make are of very high quality.
I think you give Turkish members here a bad name, just like some Chinese members here who preach their fanboyism about their own weapons. Currently, almost all major Chinese aircraft are produced with Chinese engines (e.g. J-20, J-10, Sino-flankers, Y-20, etc). Chinese tank engines have also become very high performance in the past decade ... it was one of the major selling points of the VT-4 tender and something Pakistan was really impressed with. This is just the truth, like it or not.
Where is the original source of these claims? I read the article and it seems like everything came out of the author's butt, unless he did not credit the original sources. Giving us the original source would help us better scrutinize the claims.