Awesome. I asked in another thread a day or two ago if there were a name we could call it which didn't reflect China's claim. I won't remember Bien Dong because I'm a stupid American who doesn't speak foreigner, but I will try to remember West Philippine Sea. Thanks!
Vietnam calls it the East Sea. Indonesia is calling part of it the Natuna Sea.
It's tough because it has been called some form of China Sea for over 600 years by almost every country and almost every official cartographic organization. Only in the past 20 years has the name come under scrutiny outside that region due to the behavior of China.
That is one of multiple reasons, but the big ones are still military and economic supremacy. If they control all shipping and fishing there, they will be far, far more powerful than they are now. They don't need the natural gas to be desperate to make it all theirs. That's just a bonus.