I suppose there is no better way to promote your military hardware, and boost exports.
But there is more to this, than about mere military exports.
NATO Turkey has been sponsoring terrorists from the Sinkiang province in China for quite a while. This creates enormous problems for China who has been trying to deal with the issue for many years. Most of the Chinese government initiatives have been focused in the Sinkiang province..........
But why not deal with it at its source....NATO Turkey, and its long history of sponsoring terrorists.
NATO Turkey has moved several thousand Sinkiang refugee families from Turkey into Northern Syria...which presumably will form a solid base for pro-Turkish support out of Syria.
By fighting with Russia in Syria, China shows its solid strategic relationship with Russia, AND discourages NATO Turkey from sending waves of Uighur terrorists from Turkey into China. ........because you never know when a J-15 might accidentally stray into NATO Turkey territory and bomb the shit out of the wrong target...as mistakes happen in war.
There may ALSO be some business opportunities for China in post conflict Syria (requiring $150 billion investment after the war) and Iraq....with greater minerals .
This gives further greater legitimacy to the SCO, and China's peaceful intentions in the world.
China Preparing to Hit Syria Jihadists Hard
Emboldened by Moscow's action in Syria, reports are that Beijing is ready to deploy its own forces to the region