Afraid of losing a large market. It's the same with Australia. OECD countries need to band together to respond to countries abusing global trade.
Things like this is the point of the EU, not creating swaths of regulations about how much or little banannas can be bent.
A place like Australia (alone) could never stand up to China. They would be too willing to make an example of a small country that crosses them. China trade comes with huge amounts of political pride and convenience. Even if Australia joined forces with a larger block we risk being g made an example of like that general saying he would sink an Australian ship to send a message to the US.
I feel in the past countries would stick to their commitment for the bigger picture. Now, not so sure. I wonder if they would weigh pros and cons and decide to withdraw or not.
Funny enough this was what the WTO was supposed to be for.