The reason was sillier: China forced Ford to sell Mazda to enter the Chinese market, because Mazda entered the Chinese market before Ford and China considered them the same entity subject to the same outside manufacturer limits).
Mazda handled the small vehicle chassis design for Ford. So without Mazda, Ford no longer had the knowledge for continued development of their sedans and crossovers based on sedan platforms.
Ford was with Mazda in China with a joint venture with a Chinese company (as required): Changan, and they were building those shared Ford/Mazda platform vehicles there.
Ford wanted to also build trucks for the Chinese market, with a different joint venture. However, the rules limited companies to two joint ventures, which was a problem because Mazda also had a joint venture with FAW. Which meant it counted as part of Ford's 2 joint ventures.
So Ford sold Mazda. Changan Ford/Mazda got split in their respective halves. FAW was no longer associated with Ford and left with Mazda. Ford could then pick up a new joint venture for trucks, which they did and I don't believe they're doing well.
Ford just really wanted to double down on trucks, in more than one market.
Wow! That IS silly! I thought Ford had been in China for a while though.