There was a comprehensive analysis of why China is such a conundrum on the Plane mad site a few weeks back.
The Chinese Airlines essentially make more money on internal flights so are reluctant to start long haul as they actually lose out.
The gap could of course be filled by EK, Etihad etc BUT the Chinese are very wary that foreign airlines will then take market share which they will not be able to get back down the line if their strategy changes
"...Damned if you do and damned if you don't".
This link may be of interest
Where in the World - The Leader's Blog
PS You cannot connect anybody at PM as the contact form link is dead so if you are thinking of joining to see the article it is impossible to contact them.
I will try and find the link for the PM article here.